PREFAB Meaning of PREFAB in English I. (ˌ)prē-ˈfab, ˈprē-ˌ adjectiveDate: 1937: produced by prefabrication : prefabricated a prefab houseII. nounDate: 1942: a prefabricated structure Merriam-Webster's Collegiate English vocabulary. Энциклопедический словарь английского языка Merriam Webster. 2003