Just beginning new climb (7)
I believe the answer is:
nascent
'just beginning' is the definition.
(I've seen this before)
'new climb' is the wordplay.
'new' becomes 'n'.
'climb' becomes 'ascent' ('ascent' can be a synonym of 'climb').
'n'+'ascent'='NASCENT'
(Other definitions for nascent that I've seen before include "Promising potential" , "Being born - scan net (anag)" , "Starting existence" , "Newly-formed" , "Beginning to develop, embryonic" .)