Hardly ever spots daughter being held back (6)
I believe the answer is:
seldom
'hardly ever' is the definition.
(thesaurus)
'spots daughter being held back' is the wordplay.
'spots' becomes 'moles'.
'daughter' becomes 'd'.
'being held' means one lot of letters goes inside another.
'back' says the letters should be written in reverse.
'moles' going around 'd' is 'modles'.
'modles' written backwards gives 'SELDOM'.
(Other definitions for seldom that I've seen before include "Models (anag)" , "Alluvium" , "on rare occasions" , "Infrequent" , "Not often, infrequently" .)