magisterial

offensively self-assured or given to exercising unwarranted power

Though she was only a third grade teacher, Ms. Martinet was magisterial in dealing with her class, lording over them like a queen.

Though I was sometimes described as magisterial, she was never so described.

The word magisterial gets kicked around a lot with reference to biographies of larger-than-life figures, but this time it goes double: Picasso has no rivals as the emblematic artist of the last century, and Richardson, now up to his third volume chronicling the painter's achievement, is well on his way toward giving his subject the biography he deserves. 14.

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