bib vs serviette

bib and serviette both are nouns.

Word	Noun	Adjective	Verb	Adverb
bib	Yes	No	Yes	No
serviette	Yes	No	No	No

As nouns, serviette is a hypernym of bib; that is, serviette is a word with a broader meaning than bib:

bib: a napkin tied under the chin of a child while eating
serviette: a small piece of table linen that is used to wipe the mouth and to cover the lap in order to protect clothing

Other hypernyms of bib include napkin, table napkin.

bib (noun)	serviette (noun)
a napkin tied under the chin of a child while eating	a small piece of table linen that is used to wipe the mouth and to cover the lap in order to protect clothing
top part of an apron; covering the chest

bib (verb)	serviette (verb)
drink moderately but regularly