1.
triplets (three children born together)
Three children born to the same mother at one birth.
2.
three-year-old child; very young child
A young child of about three. This older sense survives mainly in the proverb below.
It is said that one's character at age three does not change even in adulthood.
Related Words
Compare:
双子 (twins)
Compare:
四つ子 (quadruplets)
Compare:
双生児 (twins (formal/medical term))