Merluccius productus, a ray-finned fish found in the northeast Pacific Ocean. / A Chinook salmon that returns to the fresh water one or two years early. / (colloquial) Sander canadensis.

plural of Jack Shalloo

(dated, naval slang) A (male) braggart. / (dated, naval slang) A careless or happy-go-lucky man.

plural of Jack Strop

(UK, naval slang) A conceited, argumentative or swaggering sailor.

The common water snake of Europe. / The venomous African viper Bitis nasicornis.

An implement for starting a railway-carriage, etc.

plural of Jack and Jill

(chiefly attributive) A bachelor party or bachelorette party to which both men and women are invited. / (rhyming slang) A bill (as for a restaurant meal). / (rhyming slang) A till.

Alternative form of jack all