And/ or (also and or) is a grammatical conjunction used to indicate that one or more of the cases it connects may occur. For example, the sentence "He will eat. OR Books is a new type of publishing company. It embraces progressive change in politics, culture and the way we do business. From Middle English or ; partially contracted from other, auther, from Old English āþor, āwþer, āhwæþer ("some, any, either"; > either); and partially from Middle. OR. OR. Coverage: (Vol. 4, No. 1 - Vol. 20, No. 4). Published by: -. Operational Research Quarterly (). -. OR. On the use of either or, see either Where a verb follows a list separated by or, the traditional rule is that the verb should be singular, as long as the things in. Use the OR function, one of the logical functions, to determine if any conditions in a test are TRUE. Example. Examples of using the OR function. Technical.