Tell wrongly (8)
I believe the answer is:
miscount
'tell wrongly' is the definition.
I can't tell whether this defines the answer.
'tell' is the wordplay.
I cannot quite see how this works, but
'tell' could be 'count' (I've seen this before) and 'count' is present in the answer.
The remaining letters 'mis' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for miscount that I've seen before include "total boob" , "Make error with 20 [ABACUS]" .)