hope vs rainbow

hope and rainbow both are nouns.

Word	Noun	Adjective	Verb	Adverb
hope	Yes	No	Yes	No
rainbow	Yes	No	No	No

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

hope (noun)	rainbow (noun)
one of the three Christian virtues	an illusory hope
grounds for feeling hopeful about the future	an arc of colored light in the sky caused by refraction of the sun's rays by rain
the general feeling that some desire will be fulfilled
a specific instance of feeling hopeful
someone (or something) on which expectations are centered

hope (verb)	rainbow (verb)
intend with some possibility of fulfilment
be optimistic; be full of hope; have hopes
expect and wish