flatfoot definitions WordNet (r) 3.0 (2005) n 1: a policeman who patrols a given region [syn: flatfoot, patrolman] 2: a foot afflicted with a fallen arch; abnormally flattened and spread out [syn: flatfoot, splayfoot, pes planus] Merriam Webster's noun (plural flatfeet) Date ... sole rests upon the ground 2. a foot affected with flatfoot 3. a. or plural flatfoots slang police officer; especially a ...