What does the cryptic crossword clue "Retirement outfit in eight fragments (7)" mean?

The definition is "Retirement". The wordplay uses an anagram. anagram of IN (synonym="IN") + EIGHT (synonym="EIGHT") = NIGHTIE The answer is NIGHTIE.

Retirement outfit in eight fragments (7)

Independent Cryptic #11856 | 18 Down | 2024-10-09 flower