One of three children or offspring born at the same birth. She is a triplet, born with two brothers.
Any set or group of three similar items regarded as a single unit. A triplet of candles decorated the mantelpiece.
In music, a group of three notes played in the time of two. The pianist skillfully incorporated triplets into the composition.
In poetry, a group or stanza of three lines, often sharing the same rhyme. The poem ends with a concise triplet that sums up the theme.
In genetics, a sequence of three nucleotides that together code for a specific amino acid or signal in DNA or RNA (a codon). Each triplet in the DNA strand corresponds to an amino acid in the resulting protein.