Stair-rail is covered in ribbing (8)
I believe the answer is:
banister
'stair-rail' is the definition.
(I've seen this before)
'is covered in ribbing' is the wordplay.
'covered in' is an insertion indicator.
'ribbing' becomes 'banter' (I can't explain this - if you can you should believe this answer much more).
'is' placed within 'banter' is 'BANISTER'.
Can you help me to learn more?
(Other definitions for banister that I've seen before include "Stair-rail" , "Upright supporting handrail of stairs" , "Staircase handrail" , "Stair handrail and supports" , "Stair rail" .)
