acid anhydrides vs acyl anhydrides

acid anhydrides and acyl anhydrides both are nouns.

Word	Noun	Adjective	Verb	Adverb
acid anhydrides	Yes	No	No	No
acyl anhydrides	Yes	No	No	No

As nouns, acid anhydrides and acyl anhydrides are synonyms defined as:

acid anhydrides and acyl anhydrides: organic compounds that react with water to form an acid

acid anhydrides (noun)	acyl anhydrides (noun)
organic compounds that react with water to form an acid	organic compounds that react with water to form an acid