Clumsily enacts mountaineering objective (6)
I believe the answer is:
ascent
'mountaineering objective' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'clumsily enacts' is the wordplay.
'clumsily' indicates anagramming the letters.
'enacts' is an anagram of 'ASCENT'.
Can you help me to learn more?
(Other definitions for ascent that I've seen before include "An up-slope" , "Acclivity" , "Enacts in climb" , "Stance (anag)" , "Act of moving upwards" .)