Noun hobby has 3 senses
- avocation, by-line, hobby, sideline, spare-time activity - an auxiliary activity
--1 is a kind of pastime, interest, pursuit
--1 has particulars: speleology, spelaeology
- hobby, hobbyhorse, rocking horse - a child's plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride
--2 is a kind of plaything, toy
--2 has parts: rocker
- hobby, Falco subbuteo - small Old World falcon formerly trained and flown at small birds
--3 is a kind of falcon
--3 is a member of Falco, genus Falco
,