Most unwaning means that something is not decreasing or fading away. Some antonyms for most unwaning could be diminishing, declining, deteriorating, or fading. If something is unwaning, it is continuing to remain strong, constant or growing. Therefore, antonyms for most unwaning could also include reducing, waning, weakening, or decreasing. Most unwaning can be associated with durability, strength or resilience, which makes its antonyms more contextual based on the situation. For example, the antonym for most unwaning in terms of someone's health could be deteriorating, whereas, for a bond or friendship, the antonym for most unwaning could be weakening.