pendant earring vs earring

pendant earring and earring both are nouns.

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

As nouns, earring is a hypernym of pendant earring; that is, earring is a word with a broader meaning than pendant earring:

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

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