Conclusion not quite so infinite (7)
I believe the answer is:
endless
'quite so infinite' is the definition.
'endless' can be an answer for 'infinite' (similar in meaning). I'm not sure about the 'quite so' bit.
'conclusion not' is the wordplay.
'conclusion' becomes 'end' (something's conclusion is its end).
'not' becomes 'less' (I've seen this in other clues).
'end'+'less'='ENDLESS'
Can you help me to learn more?
(Other definitions for endless that I've seen before include "Sister of Aaron (Exodus)" , "Eternal - unbroken" , "Potentially boring" , "Continuous - eternal - incessant" , "Constant" .)