Heartfelt describes feelings or words that come from deep, genuine emotion. When you give a heartfelt apology, you truly mean it: you're sincerely sorry and genuinely regret what happened, not just saying the words because someone told you to. When someone offers heartfelt thanks, you can feel the sincerity and warmth behind their words.

The word combines heart (the symbol of our deepest feelings) with felt (experienced). A heartfelt compliment touches you differently than an offhand “nice job” because you sense the person really thought about what they said. A heartfelt letter to a grandparent means more than a hastily scribbled birthday card because the reader can feel your genuine care in every sentence.

You'll recognize heartfelt expressions because they carry emotional weight. When a coach gives a heartfelt speech after a tough loss, the team feels understood and encouraged. When a friend offers heartfelt condolences after your pet dies, their sympathy feels real and comforting. The opposite of heartfelt would be hollow, mechanical, or insincere: words spoken out of obligation rather than real feeling.