"Gehennas", derived from Greek, refers to a fiery place of punishment in the afterlife. When it comes to antonyms for this word, we can explore terms that are associated with comfort, peace or heaven. Words like paradise, Eden, heaven, Elysium, and nirvana fit this description. Other antonyms for "gehennas" could include terms like bliss, serenity, tranquility, and solace. These words evoke a sense of calmness, and a lack of suffering or punishment. As such, the antonyms for "gehennas" exist in direct contrast to the agonizing and torturous existence that is associated with the word.