Crossword Genius

'Tabloid Kelvin' is done for (4)

Ross

I believe the answer is:

'done for' is the definition.
('sunk' can be a synonym of 'done for')

'tabloid kelvin' is the wordplay.
'tabloid' becomes 'sun' (The Sun, UK newspaper).
'kelvin' becomes 'k' ('K' can be a synonym of 'kelvin').
'sun'+'k'='SUNK'

'is' acts as a link.

(Other definitions for sunk that I've seen before include "Sent to bed", "Doomed - bored", "(Has) disappeared beneath the waves", "Submerged", "suffered decline".)

I've seen this clue in The Independent.