adamant vs intransigent

adamant is a noun but intransigent is not a noun.

Word	Noun	Adjective	Verb	Adverb
adamant	Yes	Yes	No	No
intransigent	No	Yes	No	No

As adjectives, adamant and intransigent are synonyms defined as:

adamant and intransigent: impervious to pleas, persuasion, requests, reason

Other synonyms of adamant include adamantine, inexorable.

adamant (noun)	intransigent (noun)
very hard native crystalline carbon valued as a gem

adamant (adjective)	intransigent (adjective)
impervious to pleas, persuasion, requests, reason	impervious to pleas, persuasion, requests, reason