Mostly reluctant crowd... (3)
I believe the answer is:
lot
'crowd' is the definition.
(I've seen this in other clues)
'mostly reluctant' is the wordplay.
'mostly' means to remove the last letter.
'reluctant' becomes 'loth' ('loth' can be a synonym of 'reluctant').
'loth' with its last letter taken away is 'LOT'.
(Other definitions for lot that I've seen before include "Fate - great number" , "Where filming may take place" , "Item for sale at auction" , "Could there be many at the auction?" , "Fortune" .)