taru-adjective, adverb taking the 'to' particle
glittering; shining; sparkling
Literary or poetic adjective/adverb describing something that glitters or shines brightly, often used with と (e.g., 晶晶と).
夜空に星が晶晶と輝いていた。
The stars glittered brightly in the night sky.
彼女の瞳は涙で晶晶と光っていた。
Her eyes shone glittering with tears.
Describes a bright, steady light (e.g., a lamp); 晶晶 emphasizes a glittering, crystalline sparkle.
Reduplication of 晶 (しょう, 'crystal, clear'), emphasizing a glittering or sparkling quality. The exact historical derivation is uncertain, but the form follows a pattern of literary reduplicative adjectives.