OK, so bench displays a different role (9)
I believe the answer is:
tolerable
'ok' is the definition.
(thesaurus)
'bench displays a different role' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
an anagram of 'role' is 'oler' which is within the answer.
This explanation may well be incorrect...
'so' is the link.
Can you help me to learn more?
(Other definitions for tolerable that I've seen before include "Mediocre" , "may be accepted?" , "Acceptable" , "Passable" , "Adequate" .)