Electrical equipment used by commercial fitter (7)
I believe the answer is:
adapter
'electrical equipment' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'by commercial fitter' is the wordplay.
'by' says to put letters next to each other.
'commercial' becomes 'ad' (abbreviation for advertisement).
'fitter' becomes 'apter' (I've seen this before).
'ad' put next to 'apter' is 'ADAPTER'.
'used' acts as a link.
Can you help me to learn more?
(Other definitions for adapter that I've seen before include "Plug attachment" , "Dear Pat (anag)" , "I could modify" , "Plug device" , "sort of plug" .)