The common name of a group of sea-birds of the genus Sterna, or sub-family Sterninæ, akin to the gulls, but having generally a more slender body, long pointed wings, and a forked tail; a sea swallow.Of the species, which are widely diffused from Arctic to extreme southern coasts, the British Museum Catalogue reckons more than 50, of which 33 are placed in the genus Sterna, and about 18 distributed in ten other genera. Of these, six are considered indigenous to the British coasts, and many more to those of North America. The common tern of Britain and North America is Sterna hirundo (or fluviatilis); the sandwich tern, the largest British species, now scarce, is S. cantiaca; the arctic tern, S. macrura; the roseate tern, S. dougalli; the little tern, S. minuta; the black tern, Hydrochelidon (formerly Sterna) nigra.

Botany. Arranged in threes; ternate.

†1. plural. [ < French un terne, formerly ternes < Latin ternās.] A double three in dice playing. (In quot. figurative.) Obsolete.

2. In a lottery: three winning numbers drawn together; a prize gained by such a drawing.

3. A group of three stanzas.

4. Mathematics. A system of three pairs of conjugate triads of planes which together contain the twenty-seven straight lines lying in a cubic surface (i.e. one represented by an equation of the third degree).

? To throw a tern or terns in dice playing.

† terned adj. Obsolete

† †ˈterning n. Obsolete