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1.
Similar to heartbreak, but less intense. Used when one is not in love, but is still hurt by someone they are/have been involved with.

This generally applies to the talking stage of a relationship, where nothing is official. Heartdent is only applicable if there has been any kind of physical interaction.
"Hey, what's up with you and noah? Are you guys still talking?"
"No, he said he didn't want a relationship. It was major heartdent."
by AquaMarina July 18, 2007