Heftily is an adjective that describes something done with great force or intensity, often referring to physical movement or action. Some synonyms for heftily include vigorously, powerfully, forcefully, strongly, decisively, and robustly. Other options may include energetically, mightily, tightly, firmly, resolutely, or assertively. These synonyms can be used interchangeably with heftily to describe actions, gestures, or movements that carry a sense of power or authority. Whether you need to describe a physical feat or someone's actions, these synonyms can help you convey a vivid picture of the force and determination of the action.