Definitions for hobbyhorseˈhɒb iˌhɔrs
Random House Webster's College Dictionary
a stick with a horse's head, or a rocking horse, ridden by children.
a figure of a horse, attached at the waist of a performer in a morris dance, pantomime, etc.
a pet idea or project.
Origin of hobbyhorse:
a topic to which one constantly reverts
"don't get him started on his hobbyhorse"
hobby, hobbyhorse, rocking horse(noun)
a child's plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride
a strong, active horse, of a middle size, said to have been originally from Ireland; an ambling nag
a stick, often with the head or figure of a horse, on which boys make believe to ride
a subject or plan upon which one is constantly setting off; a favorite and ever-recurring theme of discourse, thought, or effort; that which occupies one's attention unduly, or to the weariness of others; a ruling passion