Conjecture with nothing right is accepted by you (8)
I believe the answer is:
theorise
'conjecture' is the definition.
('theorise' can be a synonym of 'conjecture')
'nothing right is accepted by you' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'right' becomes 'r' (common abbreviation).
'accepted by' indicates putting letters inside.
'you' becomes 'thee' (I've seen this in other clues).
'o'+'r'+'is'='oris'
'oris' placed into 'thee' is 'THEORISE'.
'with' is the link.
(Other definitions for theorise that I've seen before include "Express ideas" , "Form of hypothesis or conjecture" , "Conjecture, hypothesise" , "Think up possible explanations" , "Form view" .)