1658, "type of insect that holds its forelegs in a praying position" (esp. the praying mantis,
Mantis religiosa), from Gk.
mantis, lit. "one who divines, a seer, prophet," from
mainesthai "be inspired," related to
menos "passion, spirit" (see
mania). The insect so called for its way of holding the forelimbs as if in prayer. Also used in Gk. for some sort of grasshopper (Theocritus).