Hair line? (7)
'hair line' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for part that I've seen before include "goodbye" , "Some; break" , "unemployed actor hopes for" , "Fraction of the whole - separate" , "Bit - leave" .)
(Other definitions for parting that I've seen before include "Aggressive remarks on leaving (from a 20?)" , "Leaving or dividing" , "Separating" , "Separation" , "splitting up" .)