flash vs heat flash

flash and heat flash both are nouns.

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

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

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

flash (noun)	heat flash (noun)
a lamp for providing momentary light to take a photograph	a flash of intense heat (as released by an atomic explosion)
a bright patch of color used for decoration or identification
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)	heat flash (adjective)
tastelessly showy

flash (verb)	heat flash (verb)
appear briefly
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