IAA vs indoleacetic acid

IAA and indoleacetic acid both are nouns.

Word	Noun	Adjective	Verb	Adverb
IAA	Yes	No	No	No
indoleacetic acid	Yes	No	No	No

As nouns, IAA and indoleacetic acid are synonyms defined as:

IAA and indoleacetic acid: a plant hormone promoting elongation of stems and roots

IAA (noun)	indoleacetic acid (noun)
Yemen-based terrorist group that supports al-Qaeda's goals; seeks to overthrow the Yemeni government and eliminate United States interests; responsible for bombings and kidnappings and killing western tourists in Yemen	a plant hormone promoting elongation of stems and roots
a plant hormone promoting elongation of stems and roots