Possibly reveals a number (7)
I believe the answer is:
several
'a number' is the definition.
(I've seen this in another clue)
'possibly reveals' is the wordplay.
'possibly' is an anagram indicator.
'reveals' with letters rearranged gives 'SEVERAL'.
(Other definitions for several that I've seen before include "Various, sundry" , "Divers" , "Reveals (anag.)" , "quite a lot" , "A good few" .)