the world > life > biology > biological processes > procreation or reproduction > [noun] > offspring > multiple offspring: triplets (3)
plural. Three children (or young) at a birth; triplets.
In various specific uses. plural. Three children at a birth; singular one of three at a birth.
plural. Three children or young born at one birth: = trine, n. 3. Also singular one of such; also attributive or as adj. Cf. thrin, n.