Bit

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."