taru-adjective, adverb taking the 'to' particle
Literary or formal word describing something overly elaborate, flashy, or showy. Often used adverbially with と (e.g., 麗々と飾る). Compare with the more common adjective 麗々しい.
See also: 麗々しい
彼女は麗々と着飾ってパーティーに現れた。
She showed up at the party dressed ostentatiously.
Reduplication of 麗 (れい, 'beautiful, lovely') with the iteration mark 々, yielding an emphatic or intensified meaning. The exact historical derivation is uncertain.