stitch vs fasten

stitch is a noun but fasten is not a noun.

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

As verbs, fasten is a hypernym of stitch; that is, fasten is a word with a broader meaning than stitch:

Other hypernyms of stitch include fix, secure.

stitch (noun)	fasten (noun)
a link or loop or knot made by an implement in knitting, crocheting, embroidery, or sewing
a sharp spasm of pain in the side resulting from running

stitch (verb)	fasten (verb)
fasten by sewing; do needlework	make tight or tighter
	become fixed or fastened
	cause to be firmly attached
	attach to