tsunami vs moving ridge

tsunami and moving ridge both are nouns.

Word	Noun	Adjective	Verb	Adverb
tsunami	Yes	No	No	No
moving ridge	Yes	No	No	No

As nouns, moving ridge is a hypernym of tsunami; that is, moving ridge is a word with a broader meaning than tsunami:

tsunami: a cataclysm resulting from a destructive sea wave caused by an earthquake or volcanic eruption
moving ridge: one of a series of ridges that moves across the surface of a liquid (especially across a large body of water)

Other hypernyms of tsunami include calamity, cataclysm, catastrophe, disaster, tragedy, wave.

tsunami (noun)	moving ridge (noun)
a cataclysm resulting from a destructive sea wave caused by an earthquake or volcanic eruption	one of a series of ridges that moves across the surface of a liquid (especially across a large body of water)