Water ice or best liquid? (6)
I believe the answer is:
sorbet
'water ice' is the definition.
(I've seen this before)
'or best liquid?' is the wordplay.
'liquid?' indicates an anagram (I've seen 'liquid' mean this).
'or'+'best'='orbest'
'orbest' with letters rearranged gives 'SORBET'.
(Other definitions for sorbet that I've seen before include "Fruit water-ice" , "Fruit juice and water ice" , "Sherbet, water-ice" , "Mushy ice drink to cleanse the palate" , "Water ice dessert" .)