Mountain climb, not an easy one abandoned (4,5)
I believe the answer is:
mont blanc
'mountain' is the definition.
(European mountain)
'climb not an easy one abandoned' is the wordplay.
I cannot really understand how this works, but
an anagram of 'not' is 'ont' which is within the answer.
'an' could be 'a' and 'a' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mont blanc that I've seen before include "Highest mountain in the?Alps" , "peak of continental Europe" , "peak form" , "High spot in France (and partly 18)" , "Highest Alpine peak" .)