Definition of bit

• piece of metal held in horses mouth by reins and used to control the horse while riding; "the horse was not accustomed to a bit"
• a unit of measurement of information (from binary + digit); the amount of information in a system having two equiprobable states; "there are 8 bits in a byte"
• the cutting part of a drill; usually pointed and threaded and is replaceable in a brace or bitstock or drill press; "he looked around for the right size bit"