What is Fraud?

Legal Definition
In law, fraud is deliberate deception to secure unfair or unlawful gain, or to deprive a victim of a legal right. Fraud itself can be a civil wrong (i.e., a fraud victim may sue the fraud perpetrator to avoid the fraud and/or recover monetary compensation), a criminal wrong (i.e., a fraud perpetrator may be prosecuted and imprisoned by governmental authorities) or it may cause no loss of money, property or legal right but still be an element of another civil or criminal wrong. The purpose of fraud may be monetary gain or other benefits, such as obtaining a driver's license or qualifying for a mortgage by way of false statements.

A hoax is a distinct concept that involves deliberate deception without the intention of gain or of materially damaging or depriving a victim.
-- Wikipedia
Legal Definition
Fraud is deliberately deceiving someone else with the intent of causing damage. This damage need not be physical damage, in fact, it is often financial. There are many different types of fraud, for example bankruptcy fraud, credit card fraud, and healthcare fraud. The precise legal definition of fraud varies by jurisdiction and by the specific fraud offence.
Legal Definition
Contracts, torts. Any trick or artifice employed by one person to induce another to fall into an error, or to detain him in it, so that he may make an agreement contrary to his interest. The fraud may consist either, first, in the misrepresentation, or, secondly, in the concealment of a material fact. Fraud, force and vexation, are odious in law. Booth, Real Actions, 250. Fraud gives no action, however, without damage; 3 T. R. 56; and in matters of contract it is merely a defence; it cannot in any case constitute a new contract. 7 Vez. 211; 2 Miles' Rep. 229. It is essentially ad hominem. 4 T. R. 337-8.

2. Fraud avoids a contract, ab initio, both at law and in equity, whether the object be to deceive the public, or third persons, or one party endeavor thereby to cheat the other. 1 Fonb. Tr. Equity, 3d ed. 66, note; 6th ed. 122, and notes; Newl. Cont. 352; 1 Bl. R. 465; Dougl. Rep. 450; 3 Burr. Rep. 1909; 3 V. & B. Rep. 42; 3 Chit. Com. Law, 155, 806, 698; 1 Sch. & Lef. 209; Verpl. Contracts, passim; Domat, Lois Civ. p. 1, 1. 4, t. 6, s. 8, n. 2.

3. The following enumeration of frauds, for which equity will grant relief, is given by Lord Hardwicke, 2 Ves. 155. 1. Fraud, dolus malus, may be actual, arising from facts and circumstances of imposition, which is the plainest case. 2. It may be apparent from the intrinsic nature and subject of the bargain itself; such as no man in his senses, and not under delusion, would make on the one hand, and such as no honest and fair man would accept on the other, which are inequitable and unconscientious bargains. 1 Lev. R. 111. 3. Fraud, which may be presumed from the circumstances and condition of the parties contracting. 4. Fraud, which may be collected and inferred in the consideration of a court of equity, from the nature and circumstances of the transaction, as being an imposition and deceit on other persons, not parties to the fraudulent agreement. 5. Fraud, in what are called catching bargains, (q. v.) with heirs, reversioners) or expectants on the life of the parents. This last seems to fall, naturally, under one or more of the preceding divisions.

4. Frauds may be also divided into actual or positive and constructive frauds.

5. An actual or positive fraud is the intentional and successful employment of any cunning, deception, or artifice, used to circumvent, cheat, or deceive another. 1 Story, Eq. Jur. §186; Dig. 4, 3, 1, 2; Id. 2, 14, 7, 9.

6. By constructive fraud is meant such a contract or act, which, though not originating in any actual evil design or contrivance to perpetrate a positive fraud or injury upon other persons, yet, by its tendency to deceive or mislead. them, or to violate private or public confidence, or to impair or injure the public interests, is deemed equally reprehensible with positive fraud, and, therefore, is prohibited by law, as within the same reason and mischief as contracts and acts done malo animo. Constructive frauds are such as are either against public policy, in violation of some special confidence or trust, or operate substantially as a fraud upon private right's, interests, duties, or intentions of third persons; or unconscientiously compromit, or injuriously affect, the private interests, rights or duties of the parties themselves. 1 Story, Eq. ch. 7, §258 to 440.

7. The civilians divide frauds into positive, which consists in doing one's self, or causing another to do, such things as induce a belief of the truth of what does not exist or negative, which consists in doing or dis-simulating certain things, in order to induce the opposite party. into error, or to retain him there. The intention to deceive, which is the characteristic of fraud, is here present. Fraud is also divided into that which has induced the contract, dolus dans causum contractui, and incidental or accidental fraud. The former is that which has been the cause or determining motive of the contract, that without which the party defrauded would not have contracted, when the artifices practised by one of the parties have been such that it is evident, without them, the other would not have contracted. Incidental or accidental fraud is that by which a person, otherwise determined to contract, is deceived on some accessories or incidents of the contract; for example, as to the quality of the object of the contract, or its price, so that he has made a bad bargain. Accidental fraud does not, according to the civilians, avoid the contract, but simply subjects the party to damages. It is otherwise where the fraud has been the determining cause of the contract, qui causam dedit contractui; in that case. the contract is void. Toull. Dr. Civ. Fr. Liv. 3, t. 3, c. 2, n. §5, n. 86, et seq. See also 1 Malleville, Analyse de la, Discusssion de Code Civil, pp. 15, 16; Bouv. Inst. Index, h. t. Vide Catching bargain; Lesion; Voluntary Conveyance.
-- Bouviers Law Dictionary
Legal Definition
Fraud consists of some deceitful practice or willful device, resorted to with intent to deprive another of his right or in some manner to do him an injury. As distinguished from negligence, it is always positive, intentional. Maher v. Hibernia Ins. Co., 67 N. Y. 292; Alexander v. Church, 53 Conn. 561, 4 Atl. 103; Studer v. Bleistein, 115 N. Y. 316, 22 N. E. 243, 7 I R. A. 702'; Moore v. Crawford, 130 U. S. 122, 9 Sup. Ct 447, 32 L. Ed. 878; Fechheimer v. Baum (C. C.) 37 Fed. 167; U. S. v. Beach (D. Ct) 71 Fed. 160; Gardner v. Heartt, 3 Denlo (N. Y.) 232; Monroe Mercantile Co. v. Arnold, 108 Ga. 449, 34 S. E. 176.

Fraud, as applied to contracts, is the cause of an error bearing on a material part of the contract, created or continued by artifice, with design to obtain some unjust advantage to the one party, or to cause an inconvenience or loss to the other. Civil Code Ln. art. 1847.

Fraud, in the sense of a court of equity, properly includes all acts, omissions, and concealments which involve a breach of legal or equitable duty, trust, or confidence justly reposed, and are injurious to another, or by which an undue and unconscientious advantage is taken of another. 1 Story, Eq. Jut. § 187.

Synonyms. The term "fraud" is sometimes used as synonymous with "covin," "collusion," or "deceit." But distinctions are properly taken in the meanings of these words, for which reference may be had to the titles Covin ; Collusion ; Deceit.

Classification. Fraud is either actual or constructive. Actual fraud consists in deceit, artifice, trick, design, some direct and active operation of the mind ; it includes cases of the intentional and successful employment of any cunning, deception, or artifice used to circumvent or cheat another; it is something said, done, or omitted by a person with the design of perpetrating what he knows to be a cheat or deception.

Constructive fraud consists in any act of commission or omission contrary to legal or equitable duty, trust, or confidence justly reposed, which is contrary to good conscience and operates to the injury of another. Or, as otherwise defined, it is an act, statement or omission which operates as a virtual fraud on an individual, or which, if generally permitted, would be prejudicial to the public welfare, and yet may have been unconnected with any selfish or evil design. Or, according to Story, constructive frauds are such acts or contracts as, though not originating in any actual evil design or contrivance to perpetrate a positive fraud or injury upon other persons, are yet, by their tendency to deceive or mislead other persons, or to violate private or public confidence, or to impair or injure the public interests, deemed equally reprehensible with actual fraud. 1 Story, Eq. Jur. § 258. And see, generally, Code Ga. 1882, § 3173; People v. Kelly, 35 Barb. (N. Y.) 457; Jackson v. Jackson, 47 Ga. 99; Hatch v. Barrett, 34 Kan. 223, 8 Pac. 129; Forker v. Brown, 10 Misc. Rep. 161, 30 N. Y. Supp. 827; Massachusetts Ben. L. Ass'n v. Robinson, 104 Ga. 256, 30 S. E. 918, 42 L. In A. 261; Haas v. Stembach, 156 III. 44, 41 N. E. 51; Newell v. Wagness, 1 N. D. 62, 44 N. W. 1014; Carty v. Connolly, 91 Cal. 15, 27 Pac. 599. Fraud is also classified as fraud in fact and fraud in law. The former is actual, positive, intentional fraud. Fraud disclosed by matters of fact, as distinguished from constructive fraud or fraud in law. McKibbin v. Martin, 64'Pa. 356, 3 Am. Rep. 588; Cook v. Burnham, 3 Kan. App. 27, 44 Pac. 447. Fraud in law is fraud in contemplation of law; fraud implied or inferred by law; fraud made out by construction of law, as distinguished from fraud found by a jury from matter of fact; constructive fraud (q. v.) See 2 Kent, Comm. 5l2-532; Delaney v. Valentine, 154 N. Y. 692, 49 N. E. 65; Burr v. Clement, 9 Colo. 1, 9 Pac. 633. Fraud is also said to be legal or positive. The former is fraud made out by legal construction or inference, or the same thing as constructive fraud. Newell v. Wagness, 1 N. D. 62, 44 N. W. 1014. Positive fraud is the same thing as actual fraud. See Douthitt v. Applegate, 33 Kan. 395, 6 Pac. 575, 52 Am. Rqp. 533.
See also
-- Black's Law Dictionary
Legal Definition
Any deceitful practice used in depriving or endeavoring to deprive another of his known right by means of some artful device or plan contrary to the plain rules of common honesty. See 5 Pa. St. 216, 47 Am. Dec. 408.
-- Ballentine's Law Dictionary