puzzle vs nonplus

puzzle is a noun but nonplus is not a noun.

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

As verbs, puzzle and nonplus are synonyms defined as:

Other synonyms of puzzle include amaze, baffle, beat, bewilder, dumbfound, flummox, get, gravel, mystify, perplex, pose, stick, stupefy, vex.

puzzle (noun)	nonplus (noun)
a game that tests your ingenuity
a particularly baffling problem that is said to have a correct solution

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