Divide up equally to sample sparkling wine, say (7)
I believe the answer is:
trisect
'divide' is the definition.
(I've seen this before)
'up equally to sample sparkling wine say' is the wordplay.
I cannot quite see how this works, but
'up' could be 'is' (I've seen this in other clues) and 'is' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trisect that I've seen before include "cut into thirds" , "breakaway group after sound test" , "Cut into three pieces" , "Cut into three parts" , "Divide into three equal parts" .)