Yet another hit: youngster displacing top two (9)
I believe the answer is:
umpteenth
'top two' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'yet another hit youngster displacing' is the wordplay.
I cannot really understand how this works, but
'youngster' could be 'teen' (teenager) and 'teen' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for umpteenth that I've seen before include "such an unspecified time?" , "Latest of goodness knows how many" , "being so late in ordering" , "Latest or last of very many" , "Nth" .)