It's heart-warming without harming what divides the Irish and the English (5)
I believe the answer is:
water
'english' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for water that I've seen before include "Colourless, odourless and tasteless liquid" , "Classical element" , "Quality of diamonds" , "Basic liquid" , "What can produce solution" .)