sweatshirt vs pullover

sweatshirt and pullover both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweatshirt	Yes	No	No	No
pullover	Yes	No	No	No

As nouns, pullover is a hypernym of sweatshirt; that is, pullover is a word with a broader meaning than sweatshirt:

sweatshirt: cotton knit pullover with long sleeves worn during athletic activity
pullover: a sweater that is put on by pulling it over the head

Other hypernyms of sweatshirt include slipover.

sweatshirt (noun)	pullover (noun)
cotton knit pullover with long sleeves worn during athletic activity	a sweater that is put on by pulling it over the head