newsbreak vs newsflash

newsbreak and newsflash both are nouns.

Word	Noun	Adjective	Verb	Adverb
newsbreak	Yes	No	No	No
newsflash	Yes	No	No	No

As nouns, newsbreak and newsflash are synonyms defined as:

newsbreak and newsflash: a short news announcement concerning some on-going news story

Other synonyms of newsbreak include flash, news bulletin.

newsbreak (noun)	newsflash (noun)
a short news announcement concerning some on-going news story	a short news announcement concerning some on-going news story