How do I solve 20 across in Daily Telegraph Cryptic 31245?

Question

Accepted Answer

20 across reads "Unusually tender name for sweetheart?" (10 letters); the answer is ENDEARMENT. It's an anagram clue: the answer is a rearrangement of letters supplied by the clue itself. Look for an indicator like 'mixed', 'broken', 'cooked', or 'wild', and find a phrase whose letters add up to the answer's length. The full step-by-step breakdown is on this page.

Unusually tender name for sweetheart? (10)

20A — Unusually tender name for sweetheart? (10) — ENDEARMENT