meaning of hobbyhorse
1. A strong, active horse, of a middle size, said to have been originally from Ireland; an ambling nag.
2. A stick, often with the head or figure of a horse, on which boys make believe to ride.
3. 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 ones attention unduly, or to the weariness of others; a ruling passion.
4. a childs plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride