preview vs advertisement

preview and advertisement both are nouns.

Word	Noun	Adjective	Verb	Adverb
preview	Yes	No	Yes	No
advertisement	Yes	No	No	No

As nouns, advertisement is a hypernym of preview; that is, advertisement is a word with a broader meaning than preview:

preview: an advertisement consisting of short scenes from a motion picture that will appear in the near future
advertisement: a public promotion of some product or service

Other hypernyms of preview include ad, advert, advertising, advertizement, advertizing.

preview (noun)	advertisement (noun)
a screening for a select audience in advance of release for the general public	a public promotion of some product or service
an advertisement consisting of short scenes from a motion picture that will appear in the near future

preview (verb)	advertisement (verb)
watch (a movie or play) before it is released to the general public