round shape vs whorl

round shape and whorl both are nouns.

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

As nouns, whorl is a hyponym of round shape; that is, whorl is a word with a more specific, narrower meaning than round shape:

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

round shape (noun)	whorl (noun)
a shape that is curved and without sharp angles	a structure consisting of something wound in a continuous series of loops
	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)