The Collaborative International Dictionary
flat foot
flat foot \flat" foot`\, flatfoot \flat"foot`\ (Med.) A foot in which the arch of the instep is flattened so that the entire sole of the foot rests upon the ground; also, the deformity, usually congential, exhibited by such a foot; splayfoot.
Usage examples of "flat foot".
Clasping the ladder cables in both hands, the Tran in the bow climbed toward them, moving smoothly for a biped balancing awkwardly on three sharp chiv instead of a flat foot.
Crabbe stumbled and his huge, flat foot caught the hem of Harrys cloak.
Legs were slightly spread, heel strike then roll to toe, stand flat foot as the next rose up in the air and forward.