Meaning of acid number

ac'id num"ber

Pronunciation: [key]
— Chem. Chem.
  1. a number expressing the acidity of a substance, equal to the number of milligrams of potassium hydroxide needed to neutralize the free fatty acids present in one gram of the substance. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.