What is Adopt?

Legal Definition
1) To vote to accept or to accept (As in to adopt a resolution)

2) To form a legal parent-child relationship with a child that is not previously yours. See Adoption.
Legal Definition
To accept, appropriate, choose or select; to make that one's own (property or act) which was not so originally. To adopt a route for the transportation of the mail means to take the steps necessary to cause the mail to be transported over that route. Rhodes v. U. S., Dev. Ct. Cl. 47.

To adopt a contract is to accept it as binding, notwithstanding some defect which entitles the party to repudiate it. Thus, when a person affirms a voidable contract, or ratifies a contract made by his agent beyond his authority, he is said to adopt it. Sweet.

To accept, consent to, and put into effective operation ; as in the case of a constitution, constitutional amendment, ordinance, or by-law. Real v. People, 42 N. Y. 282; People v. Norton, 59 Barb. (N. Y.) 191.

To take into one's family the child of another and give him or her the rights, privileges, and duties of a child and heir. State v. Thompson, 13 La. Ann. 515; Abney v. De Loach, 84 Ala. 393, 4 South. 757; In re Sessions' Estate, 70 Mich. 297, 38 N. W. 249, 14 Am. St. Rep. 500; Smith v. Allen, 32 App. Div. 374, 53 N. Y. Supp. 114.

Adoption of children was a thing unknown to the common law, but was a familiar practice under the Roman law and in those countries where the civil law prevails, as France and Spain. Modem statutes authorizing adoption are taken from the civi] law, and to that extent modify the rules of the common law as to the succession of property. Butterfield v. Sawyer, 187 111. 598, 58 N. E. 602, 52 L. R. A. 75, 79 Am. St. Rep. 246; Vidal v. Commagere, 13 La, Ann. 516; Eckford v. Knox, 07 Tex. 200, 2 St W. 372.

See Adoption and legitimation.
-- Black's Law Dictionary