fasten vs secure

fasten is not an adjective while secure is an adjective.

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

As verbs, fasten and secure are synonyms defined as:

Other synonyms of fasten include fix.

fasten (adjective)	secure (adjective)
	free from fear or doubt; easy in mind
	free from danger or risk
	not likely to fail or give way
	immune to attack; incapable of being tampered with
	financially safe

fasten (verb)	secure (verb)
make tight or tighter	make certain of
become fixed or fastened	cause to be firmly attached
cause to be firmly attached	fill or close tightly with or as if with a plug
attach to	furnish with battens
	get by special effort
	assure payment of