/ Dictionary / Index T Type I error: Meaning and Definition of Find definitions for: Type I error Pronunciation: [key] the error made in the statistical testing of a hypothesis by rejecting the null hypothesis when it is actually true. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Type I diabetes Type II diabetes Related Content Daily Word Quiz: wizened Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language