Article ignored by grubby family member (5)
I believe the answer is:
uncle
'family member' is the definition.
(brother of a parent)
'article ignored by grubby' is the wordplay.
'article' becomes 'an' (indefinite article).
'ignored by' indicates named letters should be taken away.
'grubby' becomes 'unclean' (similar in meaning).
'unclean' with 'an' taken out is 'UNCLE'.
(Other definitions for uncle that I've seen before include "Family relative" , "Pawnbroker's nickname" , "Sam, perhaps" , "Brother of one's parent" , "A parent's brother" .)