Noun
A group of many parts, particularly
Coordinate terms: singlet, couplet, triplet, quadruplet, tetraplet, pentuplet, sextuplet, septuplet, octuplet, nonuplet, decuplet
(physics) A spectral line that has multiple components.
(chemistry) A compound peak produced in several forms of spectroscopy.
(physics) Any of several groupings of subatomic particles that share most properties, but have different charges.
Source: en.wiktionary.org