From the large one made squash: a soft drink (8)
I believe the answer is:
lemonade
'a soft drink' is the definition.
(I've seen this before)
'from the large one made' is the wordplay.
'from' indicates anagramming the letters (from the letters).
'the large' becomes 'l'.
'l'+'one'+'made'='lonemade'
'lonemade' with letters rearranged gives 'LEMONADE'.
'squash' is the link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for lemonade that I've seen before include "Mo leaned on the drink" , "Sweetened beverage of diluted juice" , "Still or fizzy drink" , "(Usually) fizzy drink" , "Sweet beverage of diluted juice" .)