say it: GIZ-moh
gizmo is a noun meaning "something unspecified whose name is either forgotten or not known". It carries 2 recorded senses.
something unspecified whose name is either forgotten or not known
“she eased the ball-shaped doodad back into its socket”
“there may be some great new gizmo around the corner that you will want to use”
a device or control that is very useful for a particular job
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 gizmo 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.