puzzle vs acrostic

puzzle and acrostic both are nouns.

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

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

puzzle: 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 puzzle include sudoku, word square, chess composition, chess problem.

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

puzzle (verb)	acrostic (verb)
be a mystery or bewildering to
be uncertain about; think about without fully understanding or being able to decide