augury vs war cloud

augury and war cloud both are nouns.

Word	Noun	Adjective	Verb	Adverb
augury	Yes	No	No	No
war cloud	Yes	No	No	No

As nouns, war cloud is a hyponym of augury; that is, war cloud is a word with a more specific, narrower meaning than augury:

Other hyponyms of augury include omen, portent, presage, prodigy, prognostic, prognostication.

augury (noun)	war cloud (noun)
an event that is experienced as indicating important things to come	an ominous sign that war threatens