lemniscate vs curved shape

lemniscate and curved shape both are nouns.

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

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

lemniscate: any of several plane algebraic curves in the shape of a figure eight
curved shape: the trace of a point whose direction of motion changes

Other hypernyms of lemniscate include curve.

lemniscate (noun)	curved shape (noun)
any of several plane algebraic curves in the shape of a figure eight	the trace of a point whose direction of motion changes