pennant vs streamer

pennant and streamer both are nouns.

Word	Noun	Adjective	Verb	Adverb
pennant	Yes	No	No	No
streamer	Yes	No	No	No

As nouns, pennant and streamer are synonyms defined as:

Other synonyms of pennant include pennon, waft.

pennant (noun)	streamer (noun)
a long flag; often tapering	long strip of cloth or paper used for decoration or advertising
a flag longer than it is wide (and often tapering)	a long flag; often tapering
the award given to the champion	a newspaper headline that runs across the full page
	light that streams