A simple step down (6)
I believe the answer is:
alight
'step down' is the definition.
(I've seen this in another clue)
'a simple' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
The remaining letters 'light' is a valid word 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 alight that I've seen before include "Disembark; on fire" , "Leave a vehicle - burning" , "Get out of train" , "Dismount" , "Descend, from a bus or train say" .)