The word "hellacious" is often used to describe something intense, extreme, or difficult to handle. Antonyms for this word could include mellow, peaceful, calm, easy, simple, and gentle. These words convey a sense of relaxation or a lack of intensity, in contrast to the strong emotions or extreme situations implied by "hellacious." Other possible antonyms might include enjoyable, pleasant, comfortable, or manageable. These words suggest a positive, comfortable experience rather than a challenging one. By using antonyms to describe something that is not hellacious, we can convey a completely different tone and atmosphere in our writing or speech.