/ Dictionary / Index R rustproofing: Meaning and Definition of Find definitions for: rust•proof•ing Pronunciation: (rust'pr"fing), [key] — n. the process of making metal rustproof. Also calleda substance used in this process. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. rustproof rust-through Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language