What winds up crass and lazy creep (5)
I believe the answer is:
sidle
'creep' is the definition.
(both can mean to move secretly or quietly)
'what winds up crass and lazy' is the wordplay.
I cannot quite understand how this works, but
'lazy' could be 'idle' (similar in meaning) and 'idle' is found in the answer.
A single letter 's' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sidle that I've seen before include "Walk obliquely" , "Move crabwise" , "Move in furtive or timid manner" , "Inch along" , "Edge along furtively" .)