“Acting on one's own authority” in Japanese
Short answer
Acting on one's own authority in Japanese is “専断” (sendan). Full meaning: arbitrary decision, using one's own discretion, acting on one's own authority.
Other ways to say “Acting on one's own authority” in Japanese
擅断
sendan arbitrary decision, using one's own discretion, acting on one's own authority
擅斷
sendan arbitrary decision, using one's own discretion, acting on one's own authority
專斷
sendan arbitrary decision, using one's own discretion, acting on one's own authority
せん断
sendan arbitrary decision, using one's own discretion, acting on one's own authority
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