(baseball) A home run.

(military) A large artillery gun or one of the largest-caliber naval guns (as on a battleship).

(computing) Storing the most significant byte of a multibyte number at a lower address than the least significant byte; that is, "big end" first.

(idiomatic) The mouth of someone who talks too much, especially by making exaggerated claims or by inappropriately revealing information.

(idiomatic, informal, ironic) Indicates that something is not important or impressive; so what.

(astronomy, especially US) A bright circumpolar asterism of the northern sky, said to resemble a ladle or cart. It is part of the constellation Ursa Major and includes the stars Mizar, Dubhe, and Alkaid. The other stars in it are Alioth, Megrez, Merak, and Phecda.

(idiomatic, informal, often sarcastic) Something very important or difficult; a matter of great concern; a considerable feat or achievement. / (idiomatic, informal) Someone very important; a VIP.

(vulgar, slang) Very large, expansive, fat, impressive, muscular, intimidating, or important

(idiomatic) Lots of money.

The totality of a situation. / (Britain, dated) The main film in a double feature. / Used other than figuratively or idiomatically: see big, picture.