He moves and hopes to be engaged (8)
I believe the answer is:
proposer
'he moves and hopes' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'be engaged' is the wordplay.
I cannot really understand how this works, but
'be' could be 'pose' (posing is a kind of being) and 'pose' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to' acts as a link.
Can you help me to learn more?
(Other definitions for proposer that I've seen before include "One coming up with" , "One putting forward motion" , "I present" , "One introducing motion" , "Nominator" .)