What does the cryptic crossword clue "Gary isn't cast in 1960s' TV series (8)" mean?

The definition is "TV series". The wordplay uses an anagram. anagram of GARY + ISN'T = STINGRAY; definition: "TV series" The answer is STINGRAY.

Gary isn't cast in 1960s' TV series (8)

Guardian Cryptic #29101 | 14 Across | 2023-06-20 flower