Main Entry: arch

Pronunciation: \ˈärch\

Function: noun

1 : an anatomical structure that resembles an arch in form or function: as a : either of two vaulted portions of the bony structure of the foot that impart elasticity to it: (1) : a longitudinal arch supported posteriorly by the basal tuberosity of the calcaneus and anteriorly by the heads of the metatarsal bones (2) : a transverse arch consisting of the metatarsals and first row of tarsals and resulting from elevation of the central anterior portion of the median longitudinal arch b : arch of the aorta
2 : a fingerprint in which all the ridges run from side to side and make no backward turn

[arch illustration]