a.1.Apt to break fences or to break out of pasture; unruly; as, breachy cattle.
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in classic literature ?
Stumps are a different thing, for they don’t shade the land; and, besides, you dig them—they make a fence that will turn anything bigger than a hog, being grand for breachy cattle.”