Each of the unclued lights (one of two words and one of three) can be preceded by the same word which solvers must state when submitting their entry. All resulting phrases are verifiable in Brewer 19th edition.
 

Across

 
1 Detached from musical backed by censor (8)
6 Thoroughfares more important than Norfolk waterways, apparently (6, hyphened)
11 Copy of period furniture with small repeat and gold backing (5)
14 Overtake again taking time out from meals (6)
16 Public showing Eastern cross by river (4)
17 Cake with bit of icing authorised at first for Athenian assembly (8)
21 They give out decorations without bits of ice (8)
25...