Sailors in revolutionary vessel destroyed by fire (5)
I believe the answer is:
burnt
'destroyed by fire' is the definition.
(I've seen this before)
'sailors in revolutionary vessel' is the wordplay.
'sailors' becomes 'rn' (abbreviation for Royal Navy).
'in' indicates putting letters inside.
'revolutionary' says the letters should be written in reverse.
'vessel' becomes 'tub' (tub is a kind of vessel**).
'tub' backwards is 'but'.
'rn' inserted inside 'but' is 'BURNT'.
(Other definitions for burnt that I've seen before include "Affected by fire" , "Incinerated" , "Ruined by overcooking" , "Damaged by fire" , "Charred" .)