Regard something as probable (6)
I believe the answer is:
expect
'regard something as probable' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for expect that I've seen before include "demand and > have prospects" , "Confidently hope" , "Be waiting for" , "Regard (someone) as likely to arrive" , "Regard (something) as likely to happen" .)