What is Trust?

Legal Definition
A trust or corporate trust is an American English term for a large business with significant market power. It is often used in a historical sense to refer to monopolies or near-monopolies in the United States during the Second Industrial Revolution in the 19th century and early 20th century.
-- Wikipedia
Legal Definition
A form of division of property rights in which for certain property the ownership (which goes to the trustee) is seperated from the beneficial enjoyment (which goes to the beneficiary). The person who transferes the property into the trust is known as the "Grantor" or "Settlor".

A right, enforceable in equity, to the beneficial enjoyment of property held by another party who actually holds legal title. The property so held may itself be called a "trust," especially if it consists entirely of invested money (i.e., a trust fund).
Legal Definition
Contracts, devises. An equitable right, title or interest in property, real or personal, distinct from its legal ownership; or it is a personal obligation for paying, delivering or performing anything, where the person trusting has no real. right or security, for by, that act he confides altogether to the faithfulness of those entrusted. This is its most general meaning, and includes deposits, bailments, and the like. In its more technical sense, it may be defined to be an obligation upon a person, arising out of a confidence reposed in him, to apply property faithfully, and according to such confidence. Willis on Trustees, 1; 4 Kent, Com. 295; 2 Fonb. Eq. 1; 1 Saund. Uses and Tr. 6; Coop. Eq. Pl. Introd. 27; 3 Bl. Com. 431.

2. Trusts were probably derived from the civil law. The fidei commissum, (q. v.) is not dissimilar to a trust.

3. Trusts are either express or implied. 1st. Express trusts are those which are created in express terms in the deed, writing or will. The terms to create an express trust will be sufficient, if it can be fairly collected upon the face of the instrument that a trust was intended. Express trusts are usually found in preliminary sealed agreements, such as marriage articles, or articles for the purchase of land; in formal conveyances, such as marriage settlements, terms for years, mortgages, assignments for the payment of debts, raising portions or other purposes; and in wills and testaments, when the bequests involve fiduciary interests for private benefit or public charity,, they may be created even by parol. 6 Watts & Serg. 97.

4. - 2d. Implied trusts are those which without being expressed, are deducible from the nature of the transaction, as matters of intent; or which are superinduced upon the transaction by operation of law, as matters of equity, independently of the particular intention of the parties.

5. The most common form of an implied trust is where property or money is delivered by one person to another, to be by the latter delivered to a third person. These implied trusts greatly extend over the business and pursuits of men: a few examples will be given.

6. When land is purchased by one man in the name of another, and the former pays the consideration money, the land will in general be held by the grantee in Trust for the person who so paid the consideration money. Com. Dig. Chancery, 3 W 3; 2 Fonbl. Eq. book 2, c. 5, §1, note a. Story, Eq. Jur. §1201.

7. When real property is purchased out of partnership funds, and the title is taken in the name of one of the partners, he will hold it in trust for all the partners. 7 Ves. jr. 453; Montague on Partn. 97, n.; Colly. Partn. 68.

8. When a contract is made for the sale of land, in equity the vendor is immediately deemed a trustee for the vendee of the estate; and the vendee, a trustee for the vendor of the purchase money; and by this means there is an equitable conversion of the property. 1 Fonbl. Eq. book 1, ch. 6, §9, note t; Story, Eq. Jur. SSSS 789, 790, 1212. See Conversion. For the origin of trusts in the civil law, see 5 Toull. Dr. Civ. Fr. liv. 3, t. 2, c. 1, n. 18; 1 Brown's Civ. Law, 190. Vide Resulting Trusts. See, generally, Bouv. Inst. Index, h. t.
-- Bouviers Law Dictionary
Legal Definition
I. An equitable or beneficial right or title to land or other property, held for the beneficiary by another person, In whom resides the legal title or ownership, recognised and enforced by courts of chancery. See Goodwin v. McMinn, 193 Pa. 646, 44 Atl. 1094, 74 Am. St. Rep. 703; Beers v. Lyon, 21 Conn. 613; Seymour v. Freer, 8 Wall. 202, 19 L. Ed. 306. An obligation arising out of a confidence reposed In the trustee or representative, who has the'legal title to property cenveyed to him, that he will faithfully apply the property according to the confidence reposed, or, in other words, acoording to the wishes of the grantor of the trust. 4 Kent, Comin. 304; Wlllis, Trustees, 2; Beers v. Lyon, 21 Conn. 613; Thornburg v. Buck, 13 Ind. App. 446, 41 N. E. 85. An equitable obligation, either express or implied, resting upon a person by reason of a eonfidenco reposed in him, to apply or deal with the property for the benefit of some other person, or for the benefit of himself and another or others, according to such confidence. McCreary v. Gewlnner, 103 Ga. 528, 29 S. E. 960. A holding of property subject to a duty of employing it or applying its proceeds according to directions given by the person from whom it was derived. Munroe v. Crouse, 59 Hun, 248, 12 N. Y. Supp. 815.
See also
-- Black's Law Dictionary
Legal Definition
An obligation upon a person, arising out of confidence reposed in him, to apply property faithfully and according to such confidence. See 6 How. (Miss.) 143, 38 Am. Dec. 433. See, also, Active trust; Passive trust; Trusts.
-- Ballentine's Law Dictionary