Suffered from having no seat (5)
I believe the answer is:
stood
'suffered' is the definition.
('stand' can be a synonym of 'suffer')
'from having no seat' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
'no' could be 'o' (resembles 0 - 'no' can mean 'zero') and 'o' is located in the answer.
The remaining letters 'std' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for stood that I've seen before include "Was situated" , "Remained upright" , "Was upstanding" , "Rose to one's feet" , "Tolerated; stayed upright" .)