Expression of postprandial satisfaction for Shakespearean character (5)
I believe the answer is:
belch
This clue is a double definition.
'expression of postprandial satisfaction' is the first definition.
(postprandial means after a meal)
'shakespearean character' is the second definition.
(Sir Toby Belch is a character in Twelfth Night)
'for' acts as a link.
(Other definitions for belch that I've seen before include "Unrefined report" , "Vent air from the stomach through the mouth" , "Violently eject" , "Eructation" , "Burp" .)