"a senseless, causeless murder" "a causeless war that never had an aim" "an apparently arbitrary and reasonless change"
having no cause or apparent cause;
"a causeless miracle" "fortuitous encounters--strange accidents of fortune" "we cannot regard artistic invention as...uncaused and unrelated to the times"
He became more irritable than ever, and it was Princess Marya who as a rule bore the brunt of his outbursts of causeless fury. 他已经变得比从前更易于激动,多半在公爵小姐玛丽亚身上发泄他那无缘无故的怒火。