grommet vs holdfast

grommet and holdfast both are nouns.

Word	Noun	Adjective	Verb	Adverb
grommet	Yes	No	No	No
holdfast	Yes	No	No	No

As nouns, holdfast is a hypernym of grommet; that is, holdfast is a word with a broader meaning than grommet:

grommet: fastener consisting of a metal ring for lining a small hole to permit the attachment of cords or lines
holdfast: restraint that attaches to something or holds something in place

Other hypernyms of grommet include fastener, fastening, fixing.

grommet (noun)	holdfast (noun)
fastener consisting of a metal ring for lining a small hole to permit the attachment of cords or lines	restraint that attaches to something or holds something in place