What does the cryptic crossword clue "Mythical boat with freight first removed (4)" mean?

The definition is "removed". The wordplay uses acrostic. ARGO (deletion) = ARGO; definition: "Mythical boat" The answer is ARGO.

Mythical boat with freight first removed (4)

Guardian Cryptic #29477 | 2 Down | 2024-09-02 flower