flash bulb vs flashbulb

flash bulb and flashbulb both are nouns.

Word	Noun	Adjective	Verb	Adverb
flash bulb	Yes	No	No	No
flashbulb	Yes	No	No	No

As nouns, flash bulb and flashbulb are synonyms defined as:

flash bulb and flashbulb: a lamp for providing momentary light to take a photograph

Other synonyms of flash bulb include flash, flash lamp, flashgun, photoflash.

flash bulb (noun)	flashbulb (noun)
a lamp for providing momentary light to take a photograph	a lamp for providing momentary light to take a photograph