phthisis vs T.B.

phthisis and T.B. both are nouns.

Word	Noun	Adjective	Verb	Adverb
phthisis	Yes	No	No	No
T.B.	Yes	No	No	No

As nouns, T.B. is a hypernym of phthisis; that is, T.B. is a word with a broader meaning than phthisis:

phthisis: involving the lungs with progressive wasting of the body
T.B.: infection transmitted by inhalation or ingestion of tubercle bacilli and manifested in fever and small lesions (usually in the lungs but in various other parts of the body in acute stages)

Other hypernyms of phthisis include TB, tuberculosis.

phthisis (noun)	T.B. (noun)
involving the lungs with progressive wasting of the body	infection transmitted by inhalation or ingestion of tubercle bacilli and manifested in fever and small lesions (usually in the lungs but in various other parts of the body in acute stages)