Crossword Genius

Is lacking compassion in backing those in deadlock (4)

Ross

I believe the answer is:

cold

I'm a little stuck... Click here to teach me more about this clue!

'deadlock' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Maybe there's an association between them I don't understand?

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for cold that I've seen before include "Unfriendly" , "Unemotional; infection" , "Mild viral infection, very common" , "Dead" , "made of stone" .)

I've seen this clue in the Irish Times (Crosaire) and the Irish Times.
Want a hint initially instead of a full solution? Install my app