Real Dictionary

-or
suffix: -or is used at the end of nouns that refer to people or things which perform a particular action.

-or in American English
a person or thing that (does a specified thing)

-or in American English 1
suffix: a suffix occurring in loanwords from Latin, directly or through Anglo-French, usually denoting a condition or property of things or persons, sometimes corresponding to qualitative adjectives ending in -id (ardor; honor; horror; liquor; pallor; squalor; to

-or in American English 2
suffix: a suffix forming animate or inanimate agent nouns, occurring originally in loanwords from Anglo-French ( debtor; lessor; tailor; traitor); it now functions in English as an orthographic variant of -er1, usually joined to bases of Latin origin, in imitatio

-or in British English 1
suffix forming nouns: a person or thing that does what is expressed by the verb

-or in British English 2
suffix forming nouns: indicating state, condition, or activity

O.R. in American English
abbreviation: owner's risk

or
conjunction: You use or to link two or more alternatives.

OR in American English
operating room

or in American English 1
a coordinating conjunction introducing an alternative
conjunction: (used to connect words, phrases, or clauses representing alternatives)
noun: a Boolean operator that returns a positive result when either or both operands are positive

or in American English 2
before; ere
abbreviation: on (one's own) recognizance

or in American English 3
the representation of the metal gold: indicated in engravings by small black dots on a white field
adjective: of the tincture, or metal, gold
noun: the tincture, or metal, gold: represented either by gold or by yellow

OR in British English
abbreviation for: operations research

or in British English 1
used to join alternatives

or in British English 2
conjunction: before; when
preposition: before

or in British English 3
adjective: of the metal gold