black bile vs body fluid

black bile and body fluid both are nouns.

Word	Noun	Adjective	Verb	Adverb
black bile	Yes	No	No	No
body fluid	Yes	No	No	No

As nouns, body fluid is a hypernym of black bile; that is, body fluid is a word with a broader meaning than black bile:

black bile: a humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy
body fluid: the liquid parts of the body

Other hypernyms of black bile include bodily fluid, humor, humour, liquid body substance.

black bile (noun)	body fluid (noun)
a humor that was once believed to be secreted by the kidneys or spleen and to cause sadness and melancholy	the liquid parts of the body