What is Profit?

Legal Definition
Profit or normal profit is a component of (implicit) costs and not a component of business profit at all. It represents the opportunity cost, as the time that the owner spends running the firm could be spent on running a different firm. The enterprise component of normal profit is thus the profit that a business owner considers necessary to make running the business worth his or her while, i.e., it is comparable to the next-best amount the entrepreneur could earn doing another job. Particularly if enterprise is not included as a factor of production, it can also be viewed a return to capital for investors including the entrepreneur, equivalent to the return the capital owner could have expected (in a safe investment), plus compensation for risk. In other words, the cost of normal profit varies both within and across industries; it is commensurate with the riskiness associated with each type of investment, as per the risk-return spectrum.

Only normal profits arise in circumstances of perfect competition when long-run economic equilibrium is reached; there is no incentive for firms to either enter or leave the industry.
-- Wikipedia
Legal Definition
In general, by this term is understood the benefit which a man derives from a thing. It is more particularly applied to such benefit as arises from his labor and skill.

2. It has, however, several other meanings. 1. Under the term profits, is comprehended the produce of the soil, whether it arise above or below the surface as herbage, wood, turf, coals, minerals, stones, also fish in a pond or running water. Profits are divided into profits a prendre, or those taken and enjoyed by the mere act of the proprietor himself; and profits a rendre, namely, such as are received at the hands of, and rendered by another. Ham. N. P. 172.

3. - 2. When land is devised to pay debts and legacies out of rents and profits, the land may be sold; otherwise, if out of the annual rents and profits. 1 Vern. 104, ca. 90.

4. - 3. The natural meaning of raising by rents and profits, is by the yearly profits but to prevent an inconvenience the word profits has, in some particular instances, been extended to any profits the land will yield, either by sale or mortgage; 1 Ch. Ca. 176; 2 Ch. Ca. 205; 2 Vern. 420; 1 P. Wms. 468; Pre. Ch. 586; 2 P. Wms. 19; 2 Ves. Jr. 481, n.; 2 Bro. Par. Cas. 418; 1 Atk. 506. Id. 550; 2 Atk. 358 where cases on raising portions in the life of parents and to the prejudice of the remainder-man are considered; and vide Powell on Mort. 90, et seq. But in no case where there are subsequent restraining words, has the word profit; been extended. Pre. Ch. 586, note, and the cases cited there; 1 Atk. 506; 2 Atk. 105.

5. - 4. A devise of profit considered, at law and in equity, a devise of the land itself. 1 Atk. 506; 1 Ves. 171 et vide 1 Ves. 42; 2 Atk. 358; 1 Bro. Ch. R. 310; 9 Mus. R. 372; 1 Pick. R. 224; 2 Pick. R. 425; 4 Pick. R. 203.

6. - 5. Where an assignment of rents and profits recites the intention of the parties then to make a security for money borrowed, and there is a covenant for further assurance, this amounts to an equitable lien, and would entitle the assignee to insist upon a mortgage. 2 Cox, 233; S. C. 1 Ves. Jr. 162; see also 3 Bro. C. C. 538; S. C. 1 Ves. Jr. 477.

7. - 6. Much doubt has arisen upon the question, whether the profit expected to arise upon maritime commerce be a proper subject of insurauce. 1 Marsh. on Ins. 94. In some countries, as Holland and France, Code de Com. 347, it is illegal to insure profits; but in England, profits expected to arise from a cargo of goods may be insured. 1 Marsh. on Ins. 97.

8. - 7. Personal representatives and trustees are generally bound to account for all the profits they make out of the assets entrusted to them. See Toll. Ex. 486; 1 Serg. & Rawle, 245; 1 T. R. 295; 1 M. & S. 412; Supp. to Ves. Jr., Notes to Wilkinson v. Strafford, 1 Ves. Jr. 32 Paley on Agency, 48, 9.

9. - 8. In cases of breach of contract, the plaintiff cannot in general recover damages for the profits he might have made. 1 R. 85, 94; S. C. 3 W. C. C. R. 184; 1 Pet. R. 172; see also 1 Yeates, 36; 11 Serg. & Rawle, 445.

10. - 9. It is a general rule that any participation in the profits of a trade or business, makes a person receiving such profits responsible as a partner. Gow on Part.; 6 Serg. & Rawle, 259; 1 Com. on Contr. 287 to 293. See generally on this subject, 3 W. C. C. R. 110; 15 Serg. & Rawle, 137; Chit. on Contr. 67; 6 Watts & Serg. 139.

11. But it is proper to observe that to make one a partner he must have such an interest in the profits as will entitle him to an account as it partner; he must be entitled to them as a principal. A clerk who receives a salary to be paid out of the profits would not be so considered, for there is a distinction between receiving the profits as sucli, and a commission on tile profits, and although this seems, at first sight, but a flimsy distinction, it appears to be a well settled rule of law. 15 S. & R. 157; 6 S. R. 259; 1 Denio, 337; 20 Wend. 70; 3 M. Gr. & So. 32; 17 Ves. 404; 1 Camp. 329; 2 H. Bl. 590; 3 M. G. & S. 651; 3 Kent, Com. 25, note (b) 4th ed.; Cary on Partn. 11; Colly on Part. p. 17; Addis on Contr. 451; 4 M. & S. 244; Russ. & Ry. 141; 3 M. & P. 48; 5 Taunt. 74; 4 T. R. 144. The Roman law, Dig. 17, 2, 44; Poth. Pand. 17, 2, 4; and the French law, 5 Duv. Dr. Civ. Fr. n. 48; 17 Dur. Dr. Fr. n. 332; Poth. du Contrat de Societe, n. 13, recognize the same distinction. Such is also the law of Scotland. Burt. Man. P. L. 178. When there are no stipulations to the contrary, the profits are to be enjoyed, and the losses borne by all the partners in equal proportions. Wats. Partn. 59, 60; Colly. Partn. 105; 6 Wend. 263; Story, Partn. 24; 7 Bligh, R. 132; Wilson & Shaw. 16.

12. - 10. A purchaser is entitled to the profits of the estate from the time fixed upon for completing the contract, whether he does or does not take possession of the estate. Sugd. on Vend. 353. See 6 Ves. Jr. 143, 352.

13. Profits among merchants are divided into gross profits and net profits. The former are the profits without any deduction for losses; the latter are the same profits, after having deducted all the losses. Story, Partn. 34.
-- Bouviers Law Dictionary
Legal Definition
1. The advance in the price of goods sold beyond the cost of purchase. The gain made by the sale of produce or manufactures, after deducting the value of the labor, materials, rents, and all expenses, together with the interest of the capital employed. Webster. See Providence Rubber Co., v. Goodyear, 9 Wall. 805, 19 In Ed. 828; Mundy v. Van Hoose, 104 Ga. 292, 30 S. Bl 783; Hinckley v. Pittsburgh Bessemer Steel Co., 121 U. S. 264, 7 Sup. Ct. 875, 30 L. Ed. 967; Prince v. Lamb, 128 Cal. 120, 60 Pan. 689; Maryland Ice Co. v. Arctic Ice Mach. Mfg. Co.., 79 Md. 103, 29 AH. 69.

2. The benefit, advantage, or pecuniary gain accruing to the owner or occupant of land from its actual use; as in the familiar phrase "rents, issues, and profits," or in the expression "mesne profits."

3. A division sometimes made of incorporeal hereditaments; as distinguished from "easements," which tend rather to the convenience than the profit of the claimant. 2 Steph. Comm.

2.
See also
-- Black's Law Dictionary
Legal Definition
The gain which comes in or is received from any business or investment where both receipts and payments are to be taken into account. See 79 Me. 411, 1 Am. St. Rep. 330, 10 Atl. 328.
-- Ballentine's Law Dictionary
Legal Definition
The positive gain from an investment after subtracting all expenses.
Legal Definition
It is total revenue minus total cost. It is th amount on which the tax is levied.
Legal Definition
Right or Privilege to use the resources belonging to someone else's land for the motive of profit