- adjective done without any reason.
- adjective decided by chance rather than by careful logical thought, happening without planning or at random
- adjective referring to something that is chosen or determined at random. Human language described as arbitrary because the words or sounds that denote objects do not reflect their features in any meaningful way, but have been chosen as a name for convenience. Onomatopoeic words such as ‘buzz’ are an exception to this.
Origin & History of “arbitrary”
Arbitrary comes ultimately from Latin arbiter ‘judge’, via the derived adjective arbitrārius. It originally meant ‘decided by one’s own discretion or judgment’, and has since broadened, and ‘worsened’, in meaning to ‘capricious’. The Latin noun has of course contributed a large number of other words to English, including arbiter (15th c.) itself, arbitrate (16th c.) (via the Latin verb arbitrārī), and arbitrament (14th c.). Arbitrage in the sense ‘buying and selling shares to make a profit’ is a 19th-century borrowing from French, where it means literally ‘arbitration’.