The word "bigheartedly" is defined as being generous and kind-hearted. However, there are a few antonyms that come to mind, such as selfishly, ungenerously, and stingily. These words convey the opposite meaning of being bighearted and suggest a lack of care for others. Being selfish is the act of prioritizing one's own needs above others, whereas being ungenerous suggests a reluctance to give or help others. Similarly, being stingy implies a tight-fisted nature, unwilling to part with anything. Thus, these antonyms of bigheartedness indicate a lack of empathy and kindness, reflecting negatively on a person's character.