in ancient Athens, "square pillar of stone topped by a carved human head" (conventionally that of Hermes), used as a milestone, boundary marker, etc., 1570s, from Latin herma, from Hermes (q.v.).
Entries linking to herm
Hermes
son of Zeus and Maia in Greek mythology; Olympian messenger and god of commerce, markets, and roads; protector of herdsmen, travelers, and rogues; giver of good luck, god of secret dealings, and conductor of the dead. from Greek Hermes, a word of unknown origin. He was identified by the Romans with their Mercury.