twins（雙胞胎）

two children or animals brought forth at a birth

Origin:
bef. 900; ME; OE twinn (adj.), getwinn (n. and adj.); akin to OFris twīne, ON tvinnr double, Goth twaihnai

triplets（三胞胎）
three children or offspring born at the same birth

Origin:
1650–60; triple + -et

quadruplets （四胞胎）

four children or offspring born at the same birth

Origin:
1780–90; quadruple + -et (modeled on triplet)

quintuplets （五胞胎）
five children or offspring born at the same birth

sextuplets （六胞胎）

six children or offspring born at the same birth

Origin:
1850–55; sextuple + -et ; cf. triplet

septuplets （七胞胎）

seven children or offspring born at the same birth

Origin:
1890–95; septuple + -et

octuplets（八胞胎）

eight offspring delivered at a single birth or

A group or combination of eight associated by common properties or behavior

nonuplets （九胞胎）

nine offspring delivered at a single birth or
one of a group of nine, especially such a multiple birth

decaplets （十胞胎）

ten offspring delivered at a single birth or
one of a group of ten babies born at the same time.