Have an attempt at composition (5)
I believe the answer is:
essay
'composition' is the definition.
(I've seen this before)
'have an attempt' is the wordplay.
I cannot really understand how this works, but
'have' could be 'say' (saying is a kind of having) and 'say' is present in the answer.
The remaining letters 'es' 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).
'at' is the link.
Can you help me to learn more?
(Other definitions for essay that I've seen before include "Make an effort to write one" , "Trial, piece of writing" , "Short literary piece: attempt" , "Old experiment" , "Written composition" .)