| adjective based on random choice or personal whim, rather than any reason or system. "his mealtimes were entirely arbitrary" synonyms: capricious, whimsical, random, chance, unpredictable; (of power or a ruling body) unrestrained and autocratic in the use of authority. "arbitrary rule by King and bishops has been made impossible" synonyms: autocratic, dictatorial, autarchic, undemocratic, despotic, tyrannical, authoritarian, high-handed; mathematics. (of a constant or other quantity) of unspecified value. |