An expert gunner or gunman. / (by extension) Someone most highly rated.

plural of top gun

(chiefly US, politics) An organized group which attempts to influence public policy and law with respect to firearms, especially as an advocate of ownership of and access to firearms by individual citizens.

Alternative spelling of snowgun

plural of snow gun

plural of smoking gun

A double-barrelled shotgun with very short barrels.

plural of Tommy gun

(literature) A dramatic principle that states that every element in a story must be necessary, and irrelevant elements should be removed.

(athletics) A gun fired to start a race. / (figuratively) A signal to start or proceed.