Quorum for a crowd? (5)
I believe the answer is:
three
'quorum for a crowd?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for three that I've seen before include "Trinity, triad" , "Square root of nine" , "Small number that still makes a crowd?" , "So many 12s today" , "Number of times N appears in this completed grid" .)