Pronunciation: (flat'foot" or, for 1, -foot'),[key] —n., —pl.-feetfor 1,-footsfor 2, 3. 1. Pathol. a. a condition in which the arch of the foot is flattened so that the entire sole rests upon the ground.
b. Also,flat foot.a foot with such an arch.
2. Slang.a police officer; cop.
3. Older Slang.a sailor.