Opinion about bad accommodation (6)
I believe the answer is:
billet
'accommodation' is the definition.
(I've seen this before)
'opinion about bad' is the wordplay.
'opinion' becomes 'bet' (bet can mean a prediction or opinion on the future).
'about' indicates putting letters inside.
'bad' becomes 'ill' (similar in meaning).
'bet' placed around 'ill' is 'BILLET'.
(Other definitions for billet that I've seen before include "Post" , "accommodation for the men" , "Piece of wood - bar of metal - place to stay" , "Requisitioned accommodation" , "Chunk of wood - lodging" .)