She felt unhearted after the breakup.

He unhearted himself from the situation and moved on.

The discovery of a new species in the deep sea is unheard of.

The news of the failed mission was unheartening.

She felt unheartened after receiving the rejection letter.

She gave an unhearty laugh at his joke.

Her apology seemed unheartfelt.

She smiled unheartily at the joke.

The news of his failure was unheartsome.

She unhearingly walked past the loud construction site.