mystifier vs acrostic

mystifier and acrostic both are nouns.

Word	Noun	Adjective	Verb	Adverb
mystifier	Yes	No	No	No
acrostic	Yes	No	No	No

As nouns, acrostic is a hyponym of mystifier; that is, acrostic is a word with a more specific, narrower meaning than mystifier:

mystifier: a particularly baffling problem that is said to have a correct solution
acrostic: a puzzle where you fill a square grid with words reading the same down as across

Other hyponyms of mystifier include sudoku, word square, chess composition, chess problem.

mystifier (noun)	acrostic (noun)
a particularly baffling problem that is said to have a correct solution	a puzzle where you fill a square grid with words reading the same down as across
	verse in which certain letters such as the first in each line form a word or message