bolt upright(redirected from bolts upright)
1. verb To suddenly sit or stand up from a reclining position. I bolted upright in bed when the phone rang in the middle of the night.
2. adjective Very erect in posture. The teacher instructed us to be bolt upright on the stage during the assembly.
Precisely perpendicular, erect in carriage, as in She sat bolt upright in her pew. This expression was used in slightly different form by Chaucer in the late 1300s: "She was ... long as a mast and upright as a bolt" ( The Miller's Tale).
bolt ˈuprightwith your back very straight in an upright position: The noise woke her suddenly and she sat bolt upright in bed.
In a rigidly vertical position: sat bolt upright.