Adjective
bolt upright (not comparable)
vertical, with the back held stiffly
to sit bolt upright, to stand bolt upright
Elly is squired about by eager young Hollywood actors with stage names such as "Dash Riprock" and "Bolt Upright". Source: Internet
For long stretches he sat bolt upright, alone on the VIP front row, staying awake through the drone of academics. Source: Internet
I sat bolt upright in bed, mentally going through the list of doors and windows and whether I'd locked them. Source: Internet
Or she would suddenly sit bolt upright, asking if her door and windows were shut. Source: Internet
When he woke on one particular night, somewhere in the dusty nowhere of west Durango, he couldn’t quite remember what had caused him to bolt upright, breathing heavy and screaming his throat raw, his hand already on his gun. Source: Internet