A device that allows water to flow in one direction only through a culvert; it is used especially to drain surface water from coastal marshes at low tide

plural of mud flap

A flap that hangs down behind a vehicle's wheel so that mud and other things kicked up by the wheel will hit the flap instead of a vehicle behind.

(rare, chiefly in the plural, vulgar, slang) A woman's labium.

An outfall fitted with a metal flap so that floodwater will not back up

(slang) The flap for defecation in a union suit.

(aviation) A small door on the bottom of an aircraft's cowling, used to direct additional airflow over the engine in order to improve cooling.

plural of cowl flap

(slang, vulgar) The labia majora.

(slang, vulgar) The labia majora.