The Collaborative International Dictionary
Bolt \Bolt\, adv. In the manner of a bolt; suddenly; straight; unbendingly. [He] came bolt up against the heavy dragoon. --Thackeray. Bolt upright.
Perfectly upright; perpendicular; straight up; unbendingly erect.
--Addison.On the back at full length. [Obs.]
--Chaucer.
Wikipedia
Bolt Upright was a rapcore music group from Hollywood, CA who were signed to Sony 550 Music.
Usage examples of "bolt upright".
Colour-Sergeant Evans was sitting bolt upright in his seat, rigid and alert in death as he had been in life: beside him lay Foster, the dashing, fiery Captain of Marines, whom death became so ill.
Then, with a muffled curse, he sat bolt upright, the action jarring her head and making her moan.
He sits bolt upright in wonder in his bedchamber, his eyes leaking blue-white fire.
Not one night passed by but he didn't relive the elf woman's blue-fire charge, or awake sitting bolt upright and drenched in sweat, dreaming of enemies he could never see or touch, but who constantly surrounded him.
Kyle snatched himself back from sleep, sat bolt upright in his bed.
And so did Vidra's as he came awake, sat bolt upright and snarled his terror, then reached out his trembling arms for his mother.