earring vs eardrop

earring and eardrop both are nouns.

Word	Noun	Adjective	Verb	Adverb
earring	Yes	No	No	No
eardrop	Yes	No	No	No

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

earring: jewelry to ornament the ear; usually clipped to the earlobe or fastened through a hole in the lobe
eardrop: an earring with a pendant ornament

Other hyponyms of earring include drop earring, pendant earring, ear cuff, ear hook earring, ear wrap, earcuff.

earring (noun)	eardrop (noun)
jewelry to ornament the ear; usually clipped to the earlobe or fastened through a hole in the lobe	an earring with a pendant ornament