tern

Any of various seabirds of the subfamily Sterninae (of the family Laridae) that are similar to gulls but are smaller and have a forked tail.

(no longer used, old-fashioned) A thing with three components; a set of three things.

(no longer used, old-fashioned) A lottery prize resulting from the favourable combination of three numbers in the draw.

(rare) Consisting of three components; ternate, threefold, triple.