The unclued lights (one of two words) can be preceded by the same word which is hidden in the completed grid. Solvers must highlight this word appropriately. All resulting phrases are verifiable in Brewer. Elsewhere, ignore one accent.

Across

 
1    Ought to be quiet when dreadfully loud (6)
7    Elysian areas of knowledge? (6)
12    Board for one in mental hospital? (9)
15    Governor’s gun brought back by a hill (9)
16    War god with worker bully (6)
20    Porridge making good man throw up (7)
21    Could be guaranteed this is treeless country? (6)
24    This could provide Mum with pie or stew (8)
27    Measure reflected in the...