popover vs muffin

popover and muffin both are nouns.

Word	Noun	Adjective	Verb	Adverb
popover	Yes	No	No	No
muffin	Yes	No	No	No

As nouns, muffin is a hypernym of popover; that is, muffin is a word with a broader meaning than popover:

popover: light hollow muffin made of a puff batter (individual Yorkshire pudding) baked in a deep muffin cup
muffin: a sweet quick bread baked in a cup-shaped pan

Other hypernyms of popover include gem.

popover (noun)	muffin (noun)
light hollow muffin made of a puff batter (individual Yorkshire pudding) baked in a deep muffin cup	a sweet quick bread baked in a cup-shaped pan