Abandonment of ski harness on the run (10)
I believe the answer is:
rakishness
'abandonment' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'ski harness on the run' is the wordplay.
'on' says to put letters next to each other.
'the run' indicates an anagram.
'ski'+'harness'='skiharness'
'skiharness' is an anagram of 'RAKISHNESS'.
'of' is the link.
Can you help me to learn more?
(Other definitions for rakishness that I've seen before include "Dissolute behaviour" , "Debauchery" .)