rush along vs flash

rush along is not a noun while flash is a noun.

Word	Noun	Adjective	Verb	Adverb
rush along	No	No	Yes	No
flash	Yes	Yes	Yes	No

As verbs, flash is a hyponym of rush along; that is, flash is a word with a more specific, narrower meaning than rush along:

Other hyponyms of rush along include barge, push forward, thrust ahead, buck, charge, shoot, shoot down, tear, dart, dash, scoot, scud, shoot.

rush along (noun)	flash (noun)
	a lamp for providing momentary light to take a photograph
	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)

rush along (adjective)	flash (adjective)
	tastelessly showy

rush along (verb)	flash (verb)
move hurridly	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