Home term used for a gauge (8)
I believe the answer is:
ohmmeter
'gauge' is the definition.
(I know that ohmmeter is a type of gauge)
'home term used' is the wordplay.
'used' indicates anagramming the letters.
'home'+'term'='hometerm'
'hometerm' with letters rearranged gives 'OHMMETER'.
'for a' is the link.
(Other definitions for ohmmeter that I've seen before include "Instrument measuring electrical resistance" , "Instrument to measure electrical resistance" , "It measures electrical resistance" , "Measurer of electrical resistance" , "shows signs of resistance" .)