Edna's about to provide a seat for a chairman (5)
I believe the answer is:
sedan
'provide a seat for a chairman' is the definition.
I can't tell whether this definition defines the answer.
'edna's about' is the wordplay.
'about' indicates an anagram.
'ednas' with letters rearranged gives 'SEDAN'.
'to' is the link.
Can you help me to learn more?
(Other definitions for sedan that I've seen before include "Saloon car (US)" , "Old carrying chair" , "A closed litter for one passenger" , "Andes (anag.)" , "Type of chair that's carried" .)