carthorseEtymologyFrom Middle English carthors, cartehors, from Old English crætehors (“a carthorse”), equivalent to cart + horse.carthorse means A large, strong horse used for pulling heavy loads. Lexicurio rates it Sui generis — a strength score of 87 out of 100.nounA large, strong horse used for pulling heavy loads.“The blacksmith's forge shone bright on the opposite side of the way, and the proprietor had the hind-leg of a carthorse in his leather-coated lap.”