What could be future of X site? It’s spurned (5)
I believe the answer is:
tense
'what could be future' is the definition.
(I've seen this before)
'x site? it's spurned' is the wordplay.
I cannot really understand how this works, but
'x' could be 'ten' (X is the Roman numeral for ten) and 'ten' is found in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' is the link.
Can you help me to learn more?
(Other definitions for tense that I've seen before include "Drawn" , "Verb form, indicates time" , "Anxious, high-strung" , "in the past, perhaps" , "Future perfect? Could be" .)