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Bit [nave]
BIT, part of a bridle, 2 Kin. 19:28; Psa. 32:9; Prov. 26:3; Isa. 37:39; Jas. 3:3; Rev. 14:20 See: Bridle.Bit [ebd]
the curb put into the mouths of horses to restrain them. The Hebrew word (metheg) so rendered in Ps. 32:9 is elsewhere translated "bridle" (2 Kings 19:28; Prov. 26:3; Isa. 37:29). Bits were generally made of bronze or iron, but sometimes also of gold or silver. In James 3:3 the Authorized Version translates the Greek word by "bits," but the Revised Version by "bridles."
Also see definition of "Bit" in Word Study