belt vs fasten

belt is a noun but fasten is not a noun.

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

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

Other hypernyms of belt include fix, secure.

belt (noun)	fasten (noun)
the act of hitting vigorously
a band to tie or buckle around the body (usually at the waist)
endless loop of flexible material between two rotating shafts or pulleys
ammunition (usually of small caliber) loaded in flexible linked strips for use in a machine gun
a vigorous blow
an elongated region where a specific condition or characteristic is found
a path or strip (as cut by one course of mowing)