/ Dictionary / Index N nonideal: Meaning and Definition of Find definitions for: non•i•de•al Pronunciation: (non"ī-dē'ul, -dēl'), [key] — adj. Physics. (of a gas or solution) differing in behavior from that of an ideal gas or solution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. nonhuman nonillion Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language