desiccant vs drying agent

desiccant and drying agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
desiccant	Yes	No	No	No
drying agent	Yes	No	No	No

As nouns, desiccant and drying agent are synonyms defined as:

desiccant and drying agent: a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)

Other synonyms of desiccant include drier, siccative.

desiccant (noun)	drying agent (noun)
a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)	a substance that promotes drying (e.g., calcium oxide absorbs water and is used to remove moisture)