Carelessly treading slope (8)
I believe the answer is:
gradient
'slope' is the definition.
(thesaurus)
'carelessly treading' is the wordplay.
'carelessly' indicates anagramming the letters.
'treading' is an anagram of 'GRADIENT'.
(Other definitions for gradient that I've seen before include "Angle of slope" , "Inclination" , "Third OT book" , "Measure of slope" , "Rise" .)