tendinitis vs inflammation

tendinitis and inflammation both are nouns.

Word	Noun	Adjective	Verb	Adverb
tendinitis	Yes	No	No	No
inflammation	Yes	No	No	No

As nouns, inflammation is a hypernym of tendinitis; that is, inflammation is a word with a broader meaning than tendinitis:

tendinitis: inflammation of a tendon
inflammation: a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat

Other hypernyms of tendinitis include redness, rubor.

tendinitis (noun)	inflammation (noun)
inflammation of a tendon	arousal to violent emotion
	the act of setting something on fire
	a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat
	the state of being emotionally aroused and worked up