What does the cryptic crossword clue "A small isle's in the drink, or one part of it (6,3)" mean?

The definition is "A small". The wordplay uses a double definition. Double definition The answer is TASMANSEA.

A small isle's in the drink, or one part of it (6,3)

Guardian Cryptic #26906 | 6 Down | 2016-06-09 flower