headline vs streamer

headline and streamer both are nouns.

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

As nouns, streamer is a hyponym of headline; that is, streamer is a word with a more specific, narrower meaning than headline:

Other hyponyms of headline include drop line, dropline, stagger head, staggered head, stephead, stepped line, screamer, banner.

headline (noun)	streamer (noun)
the heading or caption of a newspaper article	long strip of cloth or paper used for decoration or advertising
	a long flag; often tapering
	a newspaper headline that runs across the full page
	light that streams

headline (verb)	streamer (verb)
publicize widely or highly, as if with a headline
provide (a newspaper page or a story) with a headline