Like an earworm caught riddling yacht (6)
I believe the answer is:
catchy
'like an earworm' is the definition.
(I've seen this in another clue)
'caught riddling yacht' is the wordplay.
I cannot really understand how this works, but
'caught' could be 'c' (cricket abbreviation) and 'c' is found in the answer.
an anagram of 'yacht' is 'atchy' which is present in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for catchy that I've seen before include "Hummable" , "Attention-grabbing" , "(Of a tune) likely to remain in one's head" , "Staying in the mind of a tune" , "Tuneful and easily remembered" .)