fasten vs seal

fasten is not a noun while seal is a noun.

Word	Noun	Adjective	Verb	Adverb
fasten	No	No	Yes	No
seal	Yes	No	Yes	No

fasten (noun)	seal (noun)
	any of numerous marine mammals that come on shore to breed; chiefly of cold regions
	a device incised to make an impression; used to secure a closing or to authenticate documents
	fastener consisting of a resinous composition that is plastic when warm; used for sealing documents and parcels and letters
	fastener that provides a tight and perfect closure
	a finishing coat applied to exclude moisture
	an indication of approved or superior status
	a stamp affixed to a document (as to attest to its authenticity or to seal it)
	the pelt or fur (especially the underfur) of a seal

fasten (verb)	seal (verb)
make tight or tighter	decide irrevocably
become fixed or fastened	hunt seals
cause to be firmly attached	close with or as if with a seal
attach to	affix a seal to
	make tight; secure against leakage
	cover with varnish