glove vs mitten

glove and mitten both are nouns.

Word	Noun	Adjective	Verb	Adverb
glove	Yes	No	No	No
mitten	Yes	No	No	No

As nouns, mitten is a hyponym of glove; that is, mitten is a word with a more specific, narrower meaning than glove:

glove: handwear: covers the hand and wrist
mitten: glove that encases the thumb separately and the other four fingers together

glove (noun)	mitten (noun)
handwear: covers the hand and wrist	glove that encases the thumb separately and the other four fingers together
the handwear used by fielders in playing baseball
boxing equipment consisting of big and padded coverings for the fists of the fighters; worn for the sport of boxing