omen vs preindication

omen and preindication both are nouns.

Word	Noun	Adjective	Verb	Adverb
omen	Yes	No	Yes	No
preindication	Yes	No	No	No

As nouns, preindication is a hypernym of omen; that is, preindication is a word with a broader meaning than omen:

omen: a sign of something about to happen
preindication: an event that is experienced as indicating important things to come

Other hypernyms of omen include augury, foretoken, sign.

omen (noun)	preindication (noun)
a sign of something about to happen	an event that is experienced as indicating important things to come

omen (verb)	preindication (verb)
indicate, as with a sign or an omen