sine wave vs undulation

sine wave and undulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
sine wave	Yes	No	No	No
undulation	Yes	No	No	No

As nouns, undulation is a hypernym of sine wave; that is, undulation is a word with a broader meaning than sine wave:

Other hypernyms of sine wave include wave.

sine wave (noun)	undulation (noun)
a wave whose waveform resembles a sine curve	(physics) a movement up and down or back and forth
	wavelike motion; a gentle rising and falling in the manner of waves
	an undulating curve