designate vs demote

designate is an adjective but demote is not an adjective.

Word	Noun	Adjective	Verb	Adverb
designate	No	Yes	Yes	No
demote	No	No	Yes	No

As verbs, demote is a hyponym of designate; that is, demote is a word with a more specific, narrower meaning than designate:

designate: give an assignment to (a person) to a post, or assign a task to (a person)
demote: assign to a lower position; reduce in rank

designate (adjective)	demote (adjective)
appointed but not yet installed in office

designate (verb)	demote (verb)
design or destine	assign to a lower position; reduce in rank
assign a name or title to
decree or designate beforehand
indicate a place, direction, person, or thing; either spatially or figuratively
give an assignment to (a person) to a post, or assign a task to (a person)