"Robustuous" is a rare and archaic term used to describe something or someone strong, healthy, and vigorous. Synonyms for "robustuous" include "sturdy," "hearty," "vigorous," "strong," "healthy," "muscular," "powerful," "hardy," "stalwart," "rugged," "resistant," "durable," "brawny," and "stout." Each of these synonyms represent the idea of a person or thing with great physical strength, an abundance of energy, and stamina to endure challenging situations. These words can be used interchangeably with "robustuous" in many contexts to convey a similar meaning of toughness, resilience, and vitality.