Give description of fish coming to harbour (7)
I believe the answer is:
portray
'give description of' is the definition.
'fish coming to harbour' is the wordplay.
'fish' becomes 'ray' (ray is a kind of fish).
'coming to' says to put letters next to each other.
'harbour' becomes 'port' (I've seen this before).
'ray' put after 'port' is 'PORTRAY'.
(Other definitions for portray that I've seen before include "Describe in words or make a picture" , "Depict in art" , "Depict, present" , "Use words to describe" , "Paint a picture" .)