A common name of certain aquatic fowls of the genus Sterna; as the great tern or sea swallow, (S. hirundo,) the black tern, the lesser tern, or hooded tern, and the foolish tern, or noddy, (S. stolida.) The brown tern, or brown gull, (S. obscura,) is considered as the young of the pewit gull or sea-crow, before molting.

Threefold; consisting of three. Tern leaves, in threes, or three by three; expressing the number of leaves in each whorl or set. Tern peduncles, three growing together from the same axil. Tern flowers, growing three and three together.