whorl vs round shape

whorl and round shape both are nouns.

Word	Noun	Adjective	Verb	Adverb
whorl	Yes	No	No	No
round shape	Yes	No	No	No

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

whorl: a round shape formed by a series of concentric circles (as formed by leaves or flower petals)
round shape: a shape that is curved and without sharp angles

whorl (noun)	round shape (noun)
a structure consisting of something wound in a continuous series of loops	a shape that is curved and without sharp angles
lock of hair in the shape of a spiral or curl
a round shape formed by a series of concentric circles (as formed by leaves or flower petals)