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.

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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

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Etymology

Origin of triplet

First recorded in 1650–60; triple + -et

Explanation

When a mammal gives birth to three offspring at the same time, each is a triplet. If you're a triplet, you've got at least two siblings right from the moment you're born. While some triplets are identical (three fetuses from a single egg), it's more likely for triplets to be fraternal (from three separate eggs). In humans, twins are more common than triplets, and multiple births of more than three are even more rare. Triplet can also mean another group of three, like three lines of poetry or three notes of music.

Example Sentences

"Materials that are triplet superconductors are a kind of 'holy grail' in quantum technology, and more specifically quantum computing," explained Linder.

From Science Daily • Feb. 21, 2026

In spinach, traces of harmful chlorophyll triplet states remained.

From Science Daily • Oct. 22, 2025

"The key to the quenching mechanism lies in how quickly and efficiently the triplet states can be deactivated," said Alessandro Agostini, researcher at the University of Padua, Italy and co-lead author of the study.

From Science Daily • Oct. 22, 2025

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

And a Spanish biochemist in New York, Severo Ochoa, launched a parallel effort to map the triplet code to corresponding amino acids.

From "The Gene" by Siddhartha Mukherjee

Related Words

• threesome
• trilogy
• triumvirate