pennant vs flag

pennant and flag both are nouns.

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

As nouns, flag is a hypernym of pennant; that is, flag is a word with a broader meaning than pennant:

pennant: a long flag; often tapering
flag: emblem usually consisting of a rectangular piece of cloth of distinctive design

As nouns, flag is a hypernym of pennant; that is, flag is a word with a broader meaning than pennant:

Other hypernyms of pennant include signal flag.

pennant (noun)	flag (noun)
a long flag; often tapering	a conspicuously marked or shaped tail
a flag longer than it is wide (and often tapering)	emblem usually consisting of a rectangular piece of cloth of distinctive design
the award given to the champion	stratified stone that splits into pieces suitable as paving stones
	flagpole used to mark the position of the hole on a golf green
	a rectangular piece of fabric used as a signalling device
	a listing printed in all issues of a newspaper or magazine (usually on the editorial page) that gives the name of the publication and the names of the editorial staff, etc.
	plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals

pennant (verb)	flag (verb)
	provide with a flag
	become less intense
	communicate or signal with a flag
	decorate with flags
	droop, sink, or settle from or as if from pressure or loss of tautness