I say, See Nick in a picturesque setting (6)
I believe the answer is:
scenic
'nick in a picturesque setting' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I can't see?
'i say see' is the wordplay.
I cannot quite see how this works, but
'i' is found in the answer.
'see' could be 'c' (the word for the letter, according to Chambers) and 'c' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for scenic that I've seen before include "Like an attractive view" , "Such a railway" , "Having nice views along the way" , "Providing beautiful views" , "Like beautiful location" .)