Definition of "ipse dixit" [ipse dixit]

• An unsupported assertion, usually by a person of standing; a dictum. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Not until he clothe himself in thunder, and make the lightning his girdle; till he wear the sun for a crown, the moon for a breastplate; the stars costly jewels encircling his brow, and the rainbow as his phylactery; not until his ipse dixit cause the immoveable pillars and imperishable foundations of the throne of the universe to crumble, and his breath extinguish the fires of immortality which glow in the bosom of Diety."