Heart

CRUX

"Here’s a helpful hint for the clue "Heart" with the answer "CRUX": "It’s the core of the matter, not the organ." This hint guides the solver toward thinking of "heart" in a metaphorical sense while avoiding direct synonyms or giving away the answer. It’s easier than the original clue but still requires a bit of deduction."

The clue "Heart" leading to the answer "CRUX" relies on a clever bit of wordplay. "Heart" can mean the central or most important part of something, not just the literal organ.