say it: HAH-bee
hobby is a noun meaning "an auxiliary activity". It carries 3 recorded senses.
an auxiliary activity
a child's plaything consisting of an imitation horse mounted on rockers; the child straddles it and pretends to ride
small Old World falcon formerly trained and flown at small birds
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for hobby come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.