Synonyms: unmotivated
Definition: without motivation
Similar words: 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: unprovoked, wanton, motiveless
Definition: occurring without motivation or provocation
Usage: motiveless malignity; unprovoked and dastardly attack- F.D.Roosevelt