Come away looking awfully coldhearted, when older constituents are abandoned (6)

I believe the answer is:

detach

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

'come away' is the definition.
(I know that come away can be written as detach)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for detach that I've seen before include "Take away -- the cad (anag)" , "Disengage (something) and remove it" , "Disengage, unfasten" , "Remove from something else, say a coupon" , "free" .)

I've seen this clue in The Irish Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.