/ Dictionary / Index Y yellow streak: Meaning and Definition of Find definitions for: yel'low streak" Pronunciation: [key] — Informal. Informal. a trait of cowardice in a person's character. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Yellowstone National Park yellowtail Related Content Daily Word Quiz: obliterate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language