cockhorse n 1: anything used as a toy horse (such as a rocking horse or one knee of an adult)
Cockhorse \Cock"horse`\, n. 1. A child's rocking-horse. [1913 Webster] Ride a cockhorse to Banbury cross. --Mother Goose. [1913 Webster] 2. A high or tall horse. [R.] [1913 Webster]
Cockhorse \Cock"horse`\, a. 1. Lifted up, as one is on a tall horse. [1913 Webster] 2. Lofty in feeling; exultant; proud; upstart. [1913 Webster] Our painted fools and cockhorse peasantry. --Marlowe. [1913 Webster]