have a yellow streak(redirected from having a yellow streak)
have a yellow streak
To have a tendency to be cowardly or easily frightened. She likes to strut around like she's the boss of the place, but she has a yellow streak running down her spine if you ever confront her on an issue. He knew what they were doing was wrong, but he had a yellow streak that kept him from intervening.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.