undulation vs curved shape

undulation and curved shape both are nouns.

Word	Noun	Adjective	Verb	Adverb
undulation	Yes	No	No	No
curved shape	Yes	No	No	No

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

Other hypernyms of undulation include curve.

undulation (noun)	curved shape (noun)
(physics) a movement up and down or back and forth	the trace of a point whose direction of motion changes
wavelike motion; a gentle rising and falling in the manner of waves
an undulating curve