white horse vs moving ridge

white horse and moving ridge both are nouns.

Word	Noun	Adjective	Verb	Adverb
white horse	Yes	No	No	No
moving ridge	Yes	No	No	No

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

white horse: a wave that is blown by the wind so its crest is broken and appears white
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 white horse include wave.

white horse (noun)	moving ridge (noun)
a wave that is blown by the wind so its crest is broken and appears white	one of a series of ridges that moves across the surface of a liquid (especially across a large body of water)