Synonyms: uncaused, causeless, fortuitous
Definition: having no cause or apparent cause
Usage: a causeless miracle; fortuitous encounters--strange accidents of fortune; we cannot regard artistic invention as...uncaused and unrelated to the times
Similar words: unintended
Definition: not deliberate
Synonyms: reasonless, causeless
Definition: having no justifying cause or reason
Usage: a senseless, causeless murder; a causeless war that never had an aim; an apparently arbitrary and reasonless change
Similar words: unmotivated
Definition: without motivation