pearl vs teardrop

pearl and teardrop both are nouns.

Word	Noun	Adjective	Verb	Adverb
pearl	Yes	No	Yes	No
teardrop	Yes	No	No	No

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

pearl: a shape that is spherical and small
teardrop: anything shaped like a falling drop (as a pendant gem on an earring)

Other hyponyms of pearl include dewdrop.

pearl (noun)	teardrop (noun)
a shade of white the color of bleached bones	a drop of the clear salty saline solution secreted by the lacrimal glands
a smooth lustrous round structure inside the shell of a clam or oyster; much valued as a jewel	anything shaped like a falling drop (as a pendant gem on an earring)
a shape that is spherical and small

pearl (verb)	teardrop (verb)
gather pearls, from oysters in the ocean