Merely a whim to overtake? (7,5)
I believe the answer is:
passing fancy
'merely a whim to overtake?' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'merely a whim to overtake?' is the wordplay.
'merely' becomes 'ing' (I am not sure about this - if you are sure you should believe this answer much more).
'a whim' becomes 'fancy' (I've seen this in another clue).
'to' says to put letters next to each other (I've seen this in other clues).
'overtake?' becomes 'pass' (as in passing on a road).
'ing'+'fancy'='ingfancy'
'ingfancy' put after 'pass' is 'PASSING FANCY'.
Can you help me to learn more?
(Another definition for passing fancy that I've seen is " wish for a second?".)