High seat is put around end of table -- most convenient (7)
I believe the answer is:
easiest
'most convenient' is the definition.
(I've seen this before)
'high seat is put around end of table' is the wordplay.
'high' indicates anagramming the letters (can mean drunk or on drugs and hence disordered).
'put around' means one lot of letters goes inside another.
'end of' indicates one should take the final letters.
The last letter of 'table' is 'e'.
'seat'+'is'='seatis'
'seatis' is an anagram of 'easist'.
'easist' placed around 'e' is 'EASIEST'.
(Other definitions for easiest that I've seen before include "Least hard" , "Most effortless" , "Most comfortable" , "Simplest" , "Most convenient" .)