1. In heart, as hard-hearted.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• heartted,
• herted,
• harted,
• hareed,
• hartted,
• nearted,
• jearted,
• uearted,
• yearted,
• hwarted,
• hsarted,
• hdarted,
• hrarted,
• hearte,
• heartsede,
• heartsead,
• Evarted,
• gereted,
• hearltet,
• heaetpea

• hearty,
• herodotus,
• Herded,
• headed,
• hatred,
• heredity,
• heated,
• heartwood,
• Heeded,
• hereditary,
• Charted,
• heater,
• Hooted,
• hated,
• heartier,
• Hoarded,
• heard,
• heaved,
• harmed,
• Darted,
• heart,
• heaped,
• healed,
• Carted,
• halted,
• Cheated,
• seated.

The adverb form of "hearted" is "wholeheartedly". For example, "He wholeheartedly supported their cause".

The adjective form of the word "hearted" is "heartfelt".