fixing vs holdfast

fixing and holdfast both are nouns.

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

As nouns, fixing and holdfast are synonyms defined as:

fixing and holdfast: restraint that attaches to something or holds something in place

Other synonyms of fixing include fastener, fastening.

fixing (noun)	holdfast (noun)
the act of putting something in working order again	restraint that attaches to something or holds something in place
the sterilization of an animal
(histology) the preservation and hardening of a tissue sample to retain as nearly as possible the same relations they had in the living body
restraint that attaches to something or holds something in place