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triplet

American  
[trip-lit] / ˈtrɪp lɪt /

noun

  1. one of three children or offspring born at the same birth.

  2. triplets, three offspring born at one birth.

  3. any group or combination of three.

  4. Prosody. three successive verses or lines, especially when rhyming and of the same length; a stanza of three lines.

  5. Also called tercet.  Music. a group of three notes to be performed in the time of two ordinary notes of the same kind.

  6. an assembled imitation gem with three parts, the center one giving the color, the top and bottom, sometimes genuine, supplying the wearing qualities.

  7. Genetics. a sequence of three nucleotides; a codon in messenger RNA and an anticodon in transfer RNA.

  8. Optics. a compound lens in which three lenses are combined.

  9. triplets, (in some card games) three cards of the same denomination.

triplet British  
/ ˈtrɪplɪt /

noun

  1. a group or set of three similar things

  2. one of three offspring born at one birth

  3. music a group of three notes played in a time value of two, four, etc

  4. chem a state of a molecule or free radical in which there are two unpaired electrons

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of triplet

First recorded in 1650–60; triple + -et

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

In this system, an electron changes its spin during absorption or emission of near-infrared light, allowing it to capture the triplet energy generated by SF.

From Science Daily • Mar. 28, 2026

"We think we may have observed a triplet superconductor," said Professor Linder.

From Science Daily • Feb. 21, 2026

"A triplet superconductor is high on the wish list of many physicists working in the field of solid state physics," said Professor Jacob Linder.

From Science Daily • Feb. 21, 2026

But there’s one in particular … it’s one where Lucero, a big pop star in Mexico, plays three versions of herself, so she’s a triplet.

From Los Angeles Times • Oct. 13, 2025

Such a triplet constitutes a proton or a neutron.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.