Mutagen vs Carcinogen Mutagen and carcinogen are two terms that have a lot in common. There is a potential that a single substance could be both of them at the same time and be only one of the two, as well.
A curb bit is a type of bit used for riding horses that uses lever action. It includes the pelham bit and the Weymouth curb along with the traditional curb bit used mainly by Western riders. Kimblewicks or Kimberwickes are modified curb bits, and a curb bit is used in a double bridle along with a bradoon.
curb. 1  a chain or strap passed around a horse's lower jaw and attached to the bit: the curb checks the horse by causing it to lower its head when the reins are pulled. 2  anything that checks, restrains, or subdues. 3  an enclosing framework. 4  a raised margin around or along an edge, to strengthen or confine.