noun
flowers; many flowers; blossoms
Emphasizes a multitude or variety of flowers; often used in poetic or descriptive contexts.
庭には色とりどりの花々が咲いている。
Colorful flowers are blooming in the garden.
春になると、公園は花々でいっぱいになる。
In spring, the park becomes full of flowers.
adverb taking the 'to' particle
beautiful; spectacular; gorgeous
Adverbial use with と, describing something as splendid or showy, often in a literary or emphatic style.
彼女は花々と着飾ってパーティーに現れた。
She appeared at the party dressed up gorgeously.
華々しい is an i-adjective meaning 'brilliant' or 'spectacular', often used for events or achievements, while 花々と is an adverbial form describing a showy appearance.
Reduplication of 花 (はな, 'flower') with rendaku voicing, yielding はなばな. The adverbial sense likely derives from the image of flowers as splendid or showy.