1862, "favoring imposed order over freedom," from authority + -an. Compare authoritative, which originally had this meaning to itself. Noun in the sense of one advocating or practicing such governance is from 1859.
1. Senior officers could be considering a coup to restore authoritarian rule.
2. His speech provides further evidence of his increasingly authoritarian approach.
3. He said he was against returning to old authoritarian ways.
4. She rebuked her lawyer for his authoritarian attitude to her clients.
5. The authoritarian policy wasn't proved to be a success.