mantis (n.)

1650s, "type of insect that holds its forelegs in a praying position" (especially the praying mantis, Mantis religiosa), Modern Latin, from Greek mantis, used of some sort of elongated insect with long forelimbs (Theocritus), literally "one who divines, a seer, prophet," from mainesthai "be inspired," related to menos "passion, spirit," from PIE *mnyo-, suffixed form of root *men- (1) "to think," with derivatives referring to qualities and states of mind or thought (compare mania and -mancy).

The insects, which live in temperate and tropical regions worldwide, are so called for its way of holding the enlarged forelimbs as if in prayer. The mantis shrimp (by 1853; earlier sea-mantis, 1690s) is so called for its resemblance to the insect.