Quenya 

cuivië-lancassë

on the brink of life

lanca

sharp edge (not of tools); sudden end

lanca ("k")noun "sharp edge (not of tools); sudden end" _("as e.g. a cliff-edge, or the clean edge of things made by hand or built, also used in transferred senses, as in kuivie-lankasse, literally 'on the brink of life', of a perilous situation in which one is likely to fall into death" VT42:8)_