(idiomatic) To operate as effectively as possible.

A fireproof door designed to stop fires spreading through buildings. / The door of a furnace offering access to the fire inside.

(idiomatic) People will be dealt with in the order they arrive.

Alternative spelling of first-come-first-served

(idiomatic) To begin firing (weapons) at something or someone.

An uncovered fire.

plural of fire station

plural of fire marshal

plural of firing squad

plural of fire ship