What does the cryptic crossword clue "Big greener fizzy drink (6,4)" mean?

The definition is "drink". The wordplay uses an anagram. anagram of BIG + GREENER = GINGERBEER; definition: "drink" The answer is GINGERBEER.

Big greener fizzy drink (6,4)

Daily Mail Cryptic #16847 | 13 Down | 2022-05-30 flower