The unclued lights (two of two words) can be all be preceded by the same word which solvers have to highlight appropriately in the completed grid. All are confirmed in Brewer apart from one, which is not listed in Chambers either (surprisingly).
 

Across

1    Spanish mansion with some basic fruit (7)
6    What IoW tourists may do, it’s said, to manatees (7, two words)
11    Sheath’s brownish-yellow area (6)
12   Protective garments we put on, releasing right arms (7)
14    Some jubilee arranged for Glaswegian porkpie merchant (5)
17    More than one giant bird — bit like a goose (6)
19    Large band putting odd Scottish item of...