Bit (�), n. [OE. bitt, bite, AS. bite, bite, fr. bītan to bite. See Bite, n. & v., and cf. Bit a morsel.] 1. The part of a bridle, usually of iron, which is inserted in the mouth of a horse, and having appendages to which the reins are fastened. Shak.
The foamy bridle with the bit of gold.
Chaucer.
2. Fig.: Anything which curbs or restrains.