pantaloon vs trousers

pantaloon and trousers both are nouns.

Word	Noun	Adjective	Verb	Adverb
pantaloon	Yes	No	No	No
trousers	Yes	No	No	No

As nouns, trousers is a hypernym of pantaloon; that is, trousers is a word with a broader meaning than pantaloon:

pantaloon: trousers worn in former times
trousers: (usually in the plural) a garment extending from the waist to the knee or ankle, covering each leg separately

Other hypernyms of pantaloon include pair of trousers, pant.

pantaloon (noun)	trousers (noun)
trousers worn in former times	(usually in the plural) a garment extending from the waist to the knee or ankle, covering each leg separately