What does the cryptic crossword clue "Taking top off, slip in recess (4)" mean?

The definition is "recess". The wordplay uses acrostic. APSE (deletion) = APSE; definition: "recess" The answer is APSE.

Taking top off, slip in recess (4)

Guardian Cryptic #29092 | 24 Down | 2023-06-09 flower