Open University about to make a proposal (8)
I believe the answer is:
overture
'a proposal' is the definition.
(I know that overture is a type of proffer)
'open university about' is the wordplay.
'open' becomes 'overt' (associated in meaning).
'university about' becomes 'ure' (I've seen this in other clues).
'overt'+'ure'='OVERTURE'
'to make' acts as a link.
(Other definitions for overture that I've seen before include "Orchestral composition as prelude, or a friendly advance" , "Musical prelude to opera or ballet" , "Introduction to, eg, an opera" , "Orchestral piece" , "Opening gambit" .)