What does the cryptic crossword clue "Cocktail of beer (without head), gin and mixer (9)" mean?

The definition is "mixer". The wordplay uses an anagram. anagram of EER GIN AND = GRENADINE; definition: "mixer" The answer is GRENADINE.

Cocktail of beer (without head), gin and mixer (9)

Times Cryptic #28791 | 16 Across | 2023-12-20 flower