sphere vs drop

sphere and drop both are nouns.

Word	Noun	Adjective	Verb	Adverb
sphere	Yes	No	No	No
drop	Yes	No	Yes	No

As nouns, drop is a hyponym of sphere; that is, drop is a word with a more specific, narrower meaning than sphere:

sphere: a solid figure bounded by a spherical surface (including the space it encloses)
drop: a shape that is spherical and small

Other hyponyms of sphere include conglobation, conglomeration, ball, globe, orb, bead, pearl.

sphere (noun)	drop (noun)
any spherically shaped artifact	the act of dropping something
a particular aspect of life or activity	a central depository where things can be left or picked up
the geographical area in which one nation is very influential	a curtain that can be lowered and raised onto a stage from the flies; often used as background scenery
the apparent surface of the imaginary sphere on which celestial bodies appear to be projected	a sudden sharp decrease in some quantity
a solid figure bounded by a spherical surface (including the space it encloses)	a free and rapid descent by the force of gravity
a three-dimensional closed surface such that every point on the surface is equidistant from the center	a predetermined hiding place for the deposit and distribution of illicit goods (such as drugs or stolen property)
a particular environment or walk of life	a steep high face of rock
	a small indefinite quantity (especially of a liquid)
	a shape that is spherical and small

sphere (verb)	drop (verb)
	give birth; used for animals
	grow progressively worse
	go down in value
	stop pursuing or acting
	change from one level to another
	lower the pitch of (musical notes)
	fall or sink into a state of exhaustion or death
	leave undone or leave out
	omit (a letter or syllable) in speaking or writing
	utter with seeming casualness
	lose (a game)
	take (a drug, especially LSD), by mouth
	remove (cargo, people, etc.) from and leave
	to remove
	cause to fall by or as if by delivering a blow
	let or cause to fall in drops
	to fall vertically
	let fall to the ground
	fall or descend to a lower place or level
	pay out
	stop associating with
	terminate an association with
	hang loosely