flash vs glimmer

flash and glimmer both are nouns.

Word	Noun	Adjective	Verb	Adverb
flash	Yes	Yes	Yes	No
glimmer	Yes	No	Yes	No

As nouns, glimmer is a hyponym of flash; that is, glimmer is a word with a more specific, narrower meaning than flash:

Other hyponyms of flash include flicker, glint, spark, gleam, gleaming, coruscation, glitter, sparkle, heat flash, lightning, streak.

flash (noun)	glimmer (noun)
a lamp for providing momentary light to take a photograph	a slight suggestion or vague understanding
a bright patch of color used for decoration or identification	a flash of light (especially reflected light)
a momentary brightness
a sudden brilliant understanding
a short news announcement concerning some on-going news story
a burst of light used to communicate or illuminate
a gaudy outward display
a sudden intense burst of radiant energy
a short vivid experience
a very short time (as the time it takes the eye to blink or the heart to beat)

flash (adjective)	glimmer (adjective)
tastelessly showy

flash (verb)	glimmer (verb)
appear briefly	shine brightly, like a star or a light
emit a brief burst of light
make known or cause to appear with great speed
protect by covering with a thin sheet of metal
run or move very quickly or hastily
gleam or glow intermittently
display proudly; act ostentatiously or pretentiously
expose or show briefly