short subject vs toon

short subject and toon both are nouns.

Word	Noun	Adjective	Verb	Adverb
short subject	Yes	No	No	No
toon	Yes	No	No	No

As nouns, toon is a hyponym of short subject; that is, toon is a word with a more specific, narrower meaning than short subject:

short subject: a brief film; often shown prior to showing the feature
toon: a film made by photographing a series of cartoon drawings to give the illusion of movement when projected in rapid sequence

Other hyponyms of short subject include animated cartoon, cartoon, newsreel.

short subject (noun)	toon (noun)
a brief film; often shown prior to showing the feature	a film made by photographing a series of cartoon drawings to give the illusion of movement when projected in rapid sequence