stearic acid vs octadecanoic acid

stearic acid and octadecanoic acid both are nouns.

Word	Noun	Adjective	Verb	Adverb
stearic acid	Yes	No	No	No
octadecanoic acid	Yes	No	No	No

As nouns, stearic acid and octadecanoic acid are synonyms defined as:

stearic acid and octadecanoic acid: a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats

stearic acid (noun)	octadecanoic acid (noun)
a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats	a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats