Clue: HungAry? Camper maybe is heading for that, faint as before (6)
Answer: VANISH
Explanation: Definition: faint as before
 VAN (camper [van], maybe) + IS + H: as the H is there in the unmodified version of the clue, it's not really true in this case that "the clue requires the addition of a single letter before if can be satisfactorily solved"