ban vs disallow

ban is a noun but disallow is not a noun.

Word	Noun	Adjective	Verb	Adverb
ban	Yes	No	Yes	No
disallow	No	No	Yes	No

As verbs, disallow is a hypernym of ban; that is, disallow is a word with a broader meaning than ban:

Other hypernyms of ban include forbid, interdict, nix, prohibit, proscribe, veto.

ban (noun)	disallow (noun)
a decree that prohibits something
an official prohibition or edict against something
100 bani equal 1 leu in Romania
100 bani equal 1 leu in Moldova
a logarithmic unit which measures information or entropy, based on base 10 logarithms and powers of 10.

ban (verb)	disallow (verb)
prohibit especially by legal means or social pressure	command against
forbid the public distribution of (a movie or a newspaper)
expel from a community or group
ban from a place of residence, as for punishment