twinkle

(noun) a rapid change in brightness; a brief spark or flash. Synonyms: scintillation, sparkling.

(noun) merriment expressed by a brightness or gleam or animation of countenance. Synonyms: sparkle, spark, light. Examples: "He had a sparkle in his eye." "There's a perpetual twinkle in his eyes."

(verb) gleam or glow intermittently. Synonyms: flash, blink, wink, winkle. Examples: "The lights were flashing."

(verb) emit or reflect light in a flickering manner. Synonyms: winkle, scintillate. Examples: "Does a constellation twinkle more brightly than a single star?."