I object, with the guys, to the reminder (7)
I believe the answer is:
memento
'the reminder' is the definition.
(I know that memento is a type of reminder)
'i object with the guys to' is the wordplay.
'i object' becomes 'me'.
'with' is a charade indicator (letters next to each other).
'the guys' becomes 'men' (guy can mean a man).
'me'+'men'+'to'='MEMENTO'
(Other definitions for memento that I've seen before include "might be kept for sentimental reasons" , "This reminds" , "Keepsake or souvenir" , "Reminder of a person or event" , "Object kept as a souvenir" .)