1) Commonly receding boundary 2) Forehead border 3) Fracture type 4) It borders on being hirsute 5) It may get higher with age 6) Kind of fracture 7) Line 8) Middle-age concern 9) Plugs can move it forward 10) Receder of note 11) Recession victim 12) Temple feature 13) This may recede 14) This often recedes with time Found on https://www.crosswordclues.com/clue/hairline
img src='http://www.jgoffin.freeserve.co.uk/abf/glossary/hairline_terminal.gif'> In desktop publishing, a hairline also refers to the thinnest line it is possible to draw or print.
Found on http://www.encyclo.co.uk/local/20184