newsletter vs newssheet

newsletter and newssheet both are nouns.

Word	Noun	Adjective	Verb	Adverb
newsletter	Yes	No	No	No
newssheet	Yes	No	No	No

As nouns, newsletter and newssheet are synonyms defined as:

newsletter and newssheet: report or open letter giving informal or confidential news of interest to a special group

newsletter (noun)	newssheet (noun)
report or open letter giving informal or confidential news of interest to a special group	report or open letter giving informal or confidential news of interest to a special group