What does the cryptic crossword clue "Let off steam, in consequence rejecting leader (4)" mean?

The definition is "Let off steam". The wordplay uses acrostic. VENT (deletion) = VENT; definition: "Let off steam," The answer is VENT.

Let off steam, in consequence rejecting leader (4)

Guardian Cryptic #29318 | 16 Down | 2024-02-29 flower