drier vs blow drier

drier and blow drier both are nouns.

Word	Noun	Adjective	Verb	Adverb
drier	Yes	No	No	No
blow drier	Yes	No	No	No

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

drier: an appliance that removes moisture
blow drier: a hand-held electric blower that can blow warm air onto the hair; used for styling hair

drier (noun)	blow drier (noun)
an appliance that removes moisture	a hand-held electric blower that can blow warm air onto the hair; used for styling hair
a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)