triplet

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A group or set of three of one kind.
2. n. One of three children born at one birth.
3. n. A group of three lines of verse.
4. n. Music A group of three notes having the time value of two notes of the same kind. Also called tercet.
5. n. Physics A multiplet with three components.
6. n. Genetics A unit of three successive nucleotides in a molecule of DNA or RNA that codes for a specific amino acid; a codon or anticodon.

Century Dictionary and Cyclopedia

1. n. A bicycle for three riders.
2. n. A collection or combination of three of a kind, or three united.
3. n. In poetry, three verses or lines riming together.
4. n. In music, a group of three tones to be performed in the time of two or four. Such groups are marked. . Compare sextuplet, decimole, etc.
5. n. A combination of three plano-convex lenses in a compound microscope, which serves to render the object clear and distinct, and free from distortion—an improvement upon the doublet (see doublet, 2); also, a hand-microscope consisting of three double-convex lenses.
6. n. In mathematics, a system of three families of surfaces such that one of each family passes through each point of space.
7. n. One of three children born at one birth.
8. n. plural Three links of chain, generally used to connect the cable with the anchor-ring.

Wiktionary

1. n. A group of three.
2. n. One one of a group of three.
3. n. One of a group of three siblings born at the same time to the same mother.
4. n. music A group of three notes played or written where two notes would ordinarily be; a form of tuplet.
5. n. physics A triquark.

GNU Webster's 1913

1. n. A collection or combination of three of a kind; three united.
2. n. (Poetry) Three verses rhyming together.
3. n. (Mus.) A group of three notes sung or played in the tree of two.
4. n. Three children or offspring born at one birth.

WordNet 3.0

1. n. the cardinal number that is the sum of one and one and one
2. n. one of three offspring born at the same time from the same pregnancy
3. n. a set of three similar things considered as a unit