Indefinitely many (7)
I believe the answer is:
umpteen
'indefinitely many' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for umpteen that I've seen before include "Guarded" , "Indefinitely large number" , "Informally, very many" , "Large but indefinite number" , "Quite a lot of (sl)" .)