The word "velocious" means quick or speedy, so the antonyms for it would be words that signify slowness or sluggishness. Some antonyms for "velocious" include slow, leisurely, sluggish, plodding, and lethargic. These words are the opposite of the fast-paced nature that "velocious" denotes. "Langorous," "listless," "crawling," and "meandering" can be other antonyms for "velocious" as they signify a lack of speed or quickness in momentum. Using antonyms of "velocious" could help in describing actions, behaviors or situations that lack speed, and for which words like "slow," or "sluggish" would be a better fit.