the core of a thing; the most essential or important part / passion; true commitment

With the utmost earnestness.

frank; sincere; artless

Wise; knowing; skilful.

Having a wicked, malignant disposition; morally bad.

(idiomatic) Very brave; brave and magnanimous.

plural of heart-failure

(archaic, rare) Inhuman; cruel. / Very fond of dogs. / Subservient and lowly, like a pet dog.

Having a generous heart or disposition; noble; liberal.

(idiomatic) Kind and well-intentioned.