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1650s, "type of insect that holds its forelegs in a praying position" (especially the praying mantis, Mantis religiosa), Modern Latin, from Greek mantis, literally "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 Greek for some sort of grasshopper (Theocritus).