"Volunteers?" (6)
'volunteers' is the definition.
('offer' can be a synonym of 'volunteer')
This is all the clue.
(Other definitions for offers that I've seen before include "Bids, tenders" , "Tenders, presents" , "volunteers" , "Presents for acceptance or rejection" , "Specially reduced prices" .)
(Other definitions for anyone that I've seen before include "Whosoever" , "Has ...here seen Kelly (music hall song)" , "Animal-hunting trip" , "A random person" , "Pick a person - doesn't matter who" .)
(Other definitions for any that I've seen before include "At all; in some degree" , "'Whatever'" , "One (unspecified)" , "One, no matter which" , "Several" .)
(Other definitions for signs on that I've seen before include "Employs" , "Hires" .)