One of the friends on "Friends" (4)
I believe the answer is:
ross
'one of the friends on friends' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ross that I've seen before include "Macbeth thane; a T. E. Lawrence pseudonym" , "US singer Diana" , "-- Dependency; -- Sea" , "Jonathan - - (TV)" , "- and Cromarty, former Scottish county" .)