secure vs fasten

secure is an adjective but fasten is not an adjective.

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

As verbs, secure and fasten are synonyms defined as:

Other synonyms of secure include fix.

secure (adjective)	fasten (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

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