One seat or many put up round the ring (5)
I believe the answer is:
stool
'one seat' is the definition.
(I know this)
'many put up round the ring' is the wordplay.
'many' becomes 'lots' (I've seen this before).
'put up' says the letters should be written in reverse.
'round' means one lot of letters goes inside another.
'the ring' becomes 'o' (letter resembling a ring).
'lots' backwards is 'stol'.
'stol' placed around 'o' is 'STOOL'.
'or' acts as a link.
(Other definitions for stool that I've seen before include "Seat without a back" , "Backless chair" , "item of furniture here" , "Small seat" , "Armless seat" .)