बिना कारण का।

अकारण चिंता से क्या फायदा।
अकारण, अनिमित्त, अनिमित्तक, अहेतु, अहेतुक

Having no justifying cause or reason.

A senseless, causeless murder.
A causeless war that never had an aim.
An apparently arbitrary and reasonless change.
causeless, reasonless