Friend on "Friends" (6)
I believe the answer is:
monica
'friend on friends' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for monica that I've seen before include "Girl's name; am icon (anag.)" , "Girl's name (sounds like name)" , "Womans name" , "Girl" , "Nice silky woman (anag) -- White House intern" .)