How do I solve 6 down in Daily Telegraph Cryptic 31239?

Question

Accepted Answer

6 down reads "Cut, grumpy having lost skin" (4 letters); the answer is ETCH. It's a deletion clue: start with a word the clue points to, then drop one or more letters. Indicators include 'endlessly' (lose the last letter), 'beheaded' (lose the first), or 'heartlessly' (lose the middle). The full step-by-step breakdown is on this page.

Cut, grumpy having lost skin (4)

6D — Cut, grumpy having lost skin (4) — ETCH