His staff helps him reach new heights (4,7)
I believe the answer is:
pole vaulter
'helps him reach new heights' is the definition.
The definition suggests a singular noun which matches the answer.
'his staff' is the wordplay.
I cannot quite see how this works, but
'staff' could be 'pole' (I've seen this before) and 'pole' is found in the answer.
The remaining letters 'vaulter' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for pole vaulter that I've seen is " Field event competitor".)