Dared do cleaner‘s job, getting round resistance (5)
I believe the answer is:
durst
'dared' is the definition.
(archaic past tense form for 'dare')
'do cleaner's job getting round resistance' is the wordplay.
'do cleaner's job' becomes 'dust' (dust can mean to clean up dust).
'getting round' means one lot of letters goes inside another.
'resistance' becomes 'r' (electronics abbreviation).
'dust' going around 'r' is 'DURST'.
(Other definitions for durst that I've seen before include "Dared to venture" , "defied once" .)