Complete order of drinks cancelled (5,3)
I believe the answer is:
round off
'complete order' is the definition.
The answer and definition can be both related to change as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'drinks cancelled' is the wordplay.
'drinks' becomes 'round' (as in a round of drinks).
'cancelled' becomes 'off' (similar in meaning).
'round'+'off'='ROUND OFF'
'of' is the link.
Can you help me to learn more?
(Other definitions for round off that I've seen before include "Conclude" , "finish" .)