a monument consisting of a four-sided shaft tapering inward from top to bottom and bearing a head or bust; those of Hermes usually had an erect penis, which passersby stroked for luck.
herm (hûrm) n.
pl.herms also her·mae (-mī) A rectangular, often tapering stone post bearing a carved head or bust, usually of Hermes, used as a boundary marker in ancient Greece and for decorative purposes in later periods.
[Latin hermēs, herma, from Greek hermēs, from Hermēs, Hermes.]