Pronunciation: (här'tl-ē),[key] —adv. 1. in a hearty manner; cordially: He was greeted heartily. 2. sincerely; genuinely: He sympathized heartily with their plight. 3. without restraint; exuberantly; vigorously: They laughed heartily. 4. with a hearty appetite: The campers ate heartily. 5. thoroughly; completely: I'm heartily sick of your complaining.