muffle vs kiln

muffle and kiln both are nouns.

Word	Noun	Adjective	Verb	Adverb
muffle	Yes	No	Yes	No
kiln	Yes	No	No	No

As nouns, kiln is a hypernym of muffle; that is, kiln is a word with a broader meaning than muffle:

muffle: a kiln with an inner chamber for firing things at a low temperature
kiln: a furnace for firing or burning or drying such things as porcelain or bricks

muffle (noun)	kiln (noun)
a kiln with an inner chamber for firing things at a low temperature	a furnace for firing or burning or drying such things as porcelain or bricks

muffle (verb)	kiln (verb)
suppress in order to conceal or hide
deaden (a sound or noise), especially by wrapping