hoax vs play a joke on

hoax is a noun but play a joke on is not a noun.

Word	Noun	Adjective	Verb	Adverb
hoax	Yes	No	Yes	No
play a joke on	No	No	Yes	No

As verbs, hoax and play a joke on are synonyms defined as:

Other synonyms of hoax include pull someone's leg.

hoax (noun)	play a joke on (noun)
something intended to deceive; deliberate trickery intended to gain an advantage

hoax (verb)	play a joke on (verb)
subject to a playful hoax or joke	subject to a playful hoax or joke
	deceive somebody