Express a view there's nothing to long for (5)
I believe the answer is:
opine
'express a view' is the definition.
(I've seen this in another clue)
'nothing to long for' is the wordplay.
I cannot really understand how this works, but
'nothing' could be 'o' (looks like zero - 0) and 'o' is found in the answer.
'long' could be 'pine' (to pine for someone is to long for them) and 'pine' is found within the answer.
No letters remain.
This explanation may well be incorrect...
'there's' acts as a link.
Can you help me to learn more?
(Other definitions for opine that I've seen before include "Conjecture" , "Consider" , "Express a point of view" , "Proffer a view" , "State as one's belief" .)