1-Down's love interest, on "Friends" (4)
I believe the answer is:
ross
(Other definitions for ross that I've seen before include "- and Cromarty, former Scottish county" , "-- And Cromarty, former county of Scotland" , "Macbeth thane; a T. E. Lawrence pseudonym" , "Diana --, Motown singer" , "Wye town; Antarctic sea" .)