What does the cryptic crossword clue "It’s scary mixing pint with single gin (5,8)" mean?

The wordplay uses an anagram. anagram of PINT + SINGLE + GIN = SPINETINGLING The answer is SPINETINGLING.

It’s scary mixing pint with single gin (5,8)

Daily Mail Cryptic #16529 | 19 Across | 2021-03-10 flower