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.
sit bolt upright
to sit up straight. Tony sat bolt upright and listened to what the teacher was saying to him. After sitting bolt upright for almost an hour in that crowded airplane, I swore I would never fly again.
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).
In a rigidly vertical position: sat bolt upright.