Create plebs, unusually decent (11)
I believe the answer is:
respectable
'decent' is the definition.
('respectable' can be similar in meaning to 'decent')
'create plebs unusually' is the wordplay.
'unusually' indicates anagramming the letters.
'create'+'plebs'='createplebs'
'createplebs' with letters rearranged gives 'RESPECTABLE'.
(Other definitions for respectable that I've seen before include "Dignified" , "Worthy, honest" , "Fit to move in society" , "Seemly" , "fit for proper society?" .)