duplicate

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Identically copied from an original.
2. adj. Existing or growing in two corresponding parts; double.
3. adj. Denoting a manner of play in cards in which partnerships or teams play the same deals and compare scores at the end: duplicate bridge.
4. n. An identical copy; a facsimile.
5. n. One that corresponds exactly to another, especially an original.
6. n. Games A card game in which partnerships or teams play the same deals and compare scores at the end.
7. v. To make an exact copy of.
8. v. To make twofold; double.
9. v. To make or perform again; repeat: a hard feat to duplicate.
10. v. To become duplicate.

Century Dictionary and Cyclopedia

1. To double; repeat; produce a second (like the first); make a copy or copies of.
2. In physiology, to divide into two by natural growth or spontaneous division: as, some in-fusorians duplicate themselves.
3. To become double; repeat or be repeated; specifically, in ecclesiastical use, to celebrate the mass or holy communion twice in the same day. See duplication.
4. Double; twofold; consisting of or relating to a pair or pairs, or to two corresponding parts: as, duplicate spines in an insect; duplicate examples of an ancient coin; duplicate proportion.
5. Consisting of a double number or quantity; multiplied by two.
6. Exactly like or corresponding to something made or done before; repeating an original; matched: as, there are many duplicate copies of this picture; a duplicate action or proceeding.
7. n. One of two or more things corresponding in every respect to each other.
8. n. Specifically, in law and com.
9. n. An instrument or writing corresponding in every particular to a first or original and of equal validity with it; an additional original.
10. n. A second copy of a document, furnished by authority when the original has been lost, defaced, or invalidated.
11. n. One of two or more things each of which corresponds in all essential respects to an original, type, or pattern; another corresponding to a first or original; another of the same kind; a copy: as, a duplicate of a bust.
12. In whist and bridge, to play the same cards over again, as nearly as possible under the same conditions, each side getting the hands originally held by its opponents.
13. In botany, folded.

Wiktionary

1. adj. being the same as another; identical. This may exclude the first identical item in a series, but usage is inconsistent.
2. v. to make a copy of
3. v. to do repeatedly; to do again
4. v. to produce something equal to
5. n. One that resembles or corresponds to another; an identical copy.

GNU Webster's 1913

1. adj. Double; twofold.
2. n. That which exactly resembles or corresponds to something else; another, correspondent to the first; hence, a copy; a transcript; a counterpart.
3. n. (Law) An original instrument repeated; a document which is the same as another in all essential particulars, and differing from a mere copy in having all the validity of an original.
4. v. To double; to fold; to render double.
5. v. To make a duplicate of (something); to make a copy or transcript of.
6. v. (Biol.) To divide into two by natural growth or spontaneous action.

WordNet 3.0

1. n. something additional of the same kind
2. adj. being two identical
3. n. a copy that corresponds to an original exactly
4. v. make a duplicate or duplicates of
5. v. duplicate or match
6. adj. identically copied from an original
7. v. make or do or perform again
8. v. increase twofold