octadecanoic acid vs stearic acid

octadecanoic acid and stearic acid both are nouns.

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

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

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

octadecanoic acid (noun)	stearic 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