Gave the impression, as one left on the trip (4,3)
I believe the answer is:
took off
'gave the impression' is the definition.
The definition and answer can be both related to change as well as being past participle verbs.
Maybe there's an association between them I don't understand?
'one left on the trip' is the wordplay.
I cannot really see how this works, but
'one' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
'on' could be 'to' and 'to' is located in the answer.
The remaining letters 'koff' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'as' is the link.
Can you help me to learn more?
(Other definitions for took off that I've seen before include "as an impressionist?" , "Produced a parody" , "Deducted" , "Became popular" , "became a success" .)