/ Dictionary / Index F factor of safety: Meaning and Definition of Find definitions for: fac'tor of safe'ty Pronunciation: [key] the ratio of the maximum stress that a structural part or other piece of material can withstand to the maximum stress estimated for it in the use for which it is designed. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. factor of production factory Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language