Acting unilaterally on one's own authority; making decisions and taking actions without consulting others (usually with a negative nuance).
彼は会議の結論を待たずに独断専行してしまった。
He acted unilaterally without waiting for the meeting's decision.
独断専行は職場の信頼を損なうことがある。
Acting unilaterally can damage trust in the workplace.
部長の独断専行でプロジェクトの計画が大きく変わった。
The manager's unilateral decisions greatly changed the project's plan.