Dormant means not active or growing but having the ability to be active at a later time. Learn more about the word, its synonyms, antonyms, and usage in sentences from the Cambridge Dictionary. Dormant comes from French dormir, "to sleep," and it refers to living things that are on a break rather than things that have died. Being dormant is being temporarily at rest , although sometimes, as with some cancer cells, things become permanently — and thankfully — dormant. Dormant means not active or growing now but able to become active or to grow in the future. Learn how to use this word with synonyms, antonyms, pictures and example sentences. Definition of dormant in the Definitions.net dictionary. Meaning of dormant . What does dormant mean ? Information and translations of dormant in the most comprehensive dictionary definitions resource on the web.