What is Indenture?

Legal Definition
An indenture is a legal contract that reflects or covers a debt or purchase obligation. It specifically refers to two types of practices: in historical usage, an indentured servant status, and in modern usage, it is an instrument used for commercial debt or real estate transaction.
-- Wikipedia
Legal Definition
Conveyancing. An instrument of writing containing a conveyance or contract between two or more persons, usually indented or cut unevenly, or in and out, on the top or, side.

2. Formerly it was common to make two instruments exactly alike, and it was then usual to write both on the same parchment, with some words or letters written between them, through which the parchment was cut, either in a straight or indented line, in such a manner as to leave one-half of the word on one part, and half on the other. The instrument usually commences with these words, "This indenture," which were not formerly sufficient, unless the parchment or paper was actually indented to make an indenture 5 Co. 20; but now, if the form of indenting the parchment be wanting, it may be supplied by being done in court, this being mere form. Besides, it would be exceedingly difficult with even the most perfect instruments, to out parchment or paper without indenting it. Vide Bac. Ab. Leases, &c. E 2; Com. Dig. Fait, C, and note d; Litt. sec. 370; Co. Litt. 143 b, 229 a; Cruise, Dig t. 32, c. 1, s. 24; 2 Bl. Com. 294; 1 Sess. Cas. 222.
-- Bouviers Law Dictionary
Legal Definition
A deed to which two or more persons are parties, and in which these enter into reciprocal and corresponding grants or obligations towards each other; whereas a deed-poll is properly one in which only the party making it executes it or binds himself by it as a deed, though the grantors or grantees therein may be several in number. 3 Washb. Real Prop. 311; Scott v. Mills, 10 N. Y. St. Rep. 358; Bowen v. Beck, 94 N. Y. 89, 46 Am. Rep. 124; Hopewell Tpv. Am-well Tp., 6 N. J. Law, 175. See Indent, v. See Indenture of apprenticeship.
-- Black's Law Dictionary
Legal Definition
A deed; an instrument drawn in two parts with toothed edges which matched when the two parts were placed together. See 6 N. J. L. 169.
-- Ballentine's Law Dictionary