Incline to be treading carelessly (8)
I believe the answer is:
gradient
'incline' is the definition.
(I've seen this before)
'treading carelessly' is the wordplay.
'carelessly' indicates an anagram.
'treading' is an anagram of 'GRADIENT'.
'to be' acts as a link.
(Other definitions for gradient that I've seen before include "Rise" , "Inclination" , "Slope or incline" , "Measure of slope" , "Bank" .)