PREFAB Meaning of PREFAB in English pre ‧ fab /ˈpriːfæb $ ˌpriːˈfæb/ BrE AmE noun [countable] [ Date: 1900-2000 ; Origin: prefabricated ] informal a small prefabricated building Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012