fit ‧ ter /ˈfɪtə $ -ər/ BrE AmE noun [countable] British English
[ Word Family: noun : ↑ fit , ↑ fitting , ↑ fitness , ↑ fitter , ↑ misfit ; adjective : ↑ fitted , ↑ fitting , ↑ fit ≠ ↑ unfit ; verb : fit; adverb : fittingly]
someone who puts together or repairs machines or equipment:
a gas fitter