Answer:

flashed

AnswerCrossword Clue
FLASHEDEmulated a firefly
FLASHEDShowed, as a grin
FLASHEDBlinked on and off
FLASHEDBriefly showed oneself in public
FLASHEDGlinted.
FLASHEDSparkled.
FLASHEDDisplayed, as a badge