diadem

Etymology

From Middle English diademe, dyademe, from Old French diademe, from Latin diadēma, from Ancient Greek διάδημα (diádēma, “band, especially worn around a tiara”), from διαδέω (diadéō, “bind around”).

noun

1. An ornamental headband worn as a badge of royalty.
2. A crown.
   The fever’d diadem on my brow I claim’d and won usurpingly —— Hath not the same fierce heirdom given Rome to the Caesar — this to me? 1829, Edgar Allan Poe, “Tamerlane”, in Al Aaraaf, Tamerlane and Minor Poems
3. Regal power; sovereignty; empire—considered as symbolized by the crown.
4. (heraldry) An arch rising from the rim of a crown (rarely also of a coronet), and uniting with others over its centre.

verb

1. To adorn with a diadem; to crown.
   The star of her destiny is the morning star of the new-born century. O’er the Golden Gate it glitters, diademming this youthful Queen of the Pacific in her robes of freedom gorgeously inlaid with gold. 1902, Horace G. Platt, “California”, in Harr Wagner, editor, Notable Speeches by Notable Speakers of the Greater West, San Francisco, Calif.: The Whitaker and Ray Company (Incorporated), page 215
   Paul cites as an example the Macedonian churches and mentions specifically several things about their liberality which adorn their grace and crown it with beauty as the lily work diademmed the pillars of the Temple. 1920 January, G. J. Rousseau, “The Grace of Liberality”, in The Homiletic Review: An International Magazine of Religion, Theology, and Philosophy; Treats Every Phase of the Minister’s Work, volume LXXIX, number 1, New York, N.Y., London: Funk and Wagnalls Company, section “Sermonic Literature”, page 72, column 1
   From many lands and from far distant climes have come great men and women to rest within our heart and to do great deeds and shape the noble events that have diademmed our crown with stars of splendor. 1921, Linwood Taft, “Historic Festival and Pageant”, in The Technique of Pageantry, New York, N.Y.: A. S. Barnes and Company, part II, page 143
   Vardan, brave champion [or, “martyr”] who routed the enemy, / You diademmed the Church in your rosy blood. 1987, The Armenian Review, page 6