The Probert Encyclopaedia of Costume

CHAPAREJOS

Chaparejos (also known as chapareras, and commonly as 'chaps') are trouser-like overalls made of sheepskin or leather, usually open at the back, worn, by Mexican cowboys, to protect the legs from thorny bushes. When closed at the back of the leg, they are known as 'shotguns' due to their resemblance to a twin barrelled shotgun.
Research Chaparejos