sphere vs round shape

sphere and round shape both are nouns.

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

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

sphere: a solid figure bounded by a spherical surface (including the space it encloses)
round shape: a shape that is curved and without sharp angles

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

sphere: a three-dimensional closed surface such that every point on the surface is equidistant from the center
round shape: a shape that is curved and without sharp angles

sphere (noun)	round shape (noun)
any spherically shaped artifact	a shape that is curved and without sharp angles
a particular aspect of life or activity
the geographical area in which one nation is very influential
the apparent surface of the imaginary sphere on which celestial bodies appear to be projected
a solid figure bounded by a spherical surface (including the space it encloses)
a three-dimensional closed surface such that every point on the surface is equidistant from the center
a particular environment or walk of life