General English


  • noun
    (written as OR)
    a Boolean function that is often used in searches to ask the search engine to find text that contains any of the search words.
  • acronymAND
    (written as OR)
  • acronym forAND
    (written as OR)


  • (written as OR)
    A logical operation which is true if any of its elements is true. For example, if one or more of its multiple inputs have a value of 1, then the output is 1. Its output is 0 only when all of its inputs have a value of 0. For such functions, a 1 is considered as a true, or high, value, and 0 is a false, or low, value. Although OR is the same as inclusive OR, the latter is used to distinguish from exclusive OR. Also called OR operation, or logical sum.


  • acronym foroperational research
    (written as OR)


  • acronym foroperating room
    (written as OR)


  • acronym forother rank
    (written as OR)
  • noun a serviceman or servicewoman who is not an officer.

Origin & History of “or”

The Old English word for ‘or’ was oththe. this appears to have been altered in the early middle English period to other, probably due to the influence of similar words denoting ‘choice between alternatives’ and ending in -er (notably either and whether). Other was soon contracted to or, but it did not finally die out until the 15th century.