kiln vs dry kiln

kiln and dry kiln both are nouns.

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

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

kiln: a furnace for firing or burning or drying such things as porcelain or bricks
dry kiln: a kiln for drying and seasoning lumber

Other hyponyms of kiln include brickkiln, limekiln, muffle, oast.

kiln (noun)	dry kiln (noun)
a furnace for firing or burning or drying such things as porcelain or bricks	a kiln for drying and seasoning lumber