| FIR | fireproof (or fire-resistant) wall designed to prevent the spread of fire through a building |
|---|---|
| FIR | (informal) any strong spirits (such as strong whisky or rum) |
| FIR | an American weedy plant with small white or greenish flowers |
| FIR | tall North American perennial with creeping rootstocks and narrow leaves and spikes of pinkish-purple flowers occurring in great abundance in burned-over areas or recent clearings |
| FIR | annual of central United States having showy long-stalked yellow flower heads marked with scarlet or purple in the center |
| FIR | eastern Australian tree widely cultivated as a shade tree and for its glossy leaves and circular clusters of showy red to orange-scarlet flowers |
| FIR | wood used for fuel |
| FIR | (usually plural) an explosive device that burns with colored flames |
| FIR | the act of discharging a gun |
| FIR | the termination of someone's employment (leaving them free to depart) |
| FIR | the act of setting on fire or catching fire |
| FIR | the act of firing weapons or artillery at an enemy |