a movable bar or rod that when slid into a socket fastens a door, gate, etc.

the part of a lock that is shot from and drawn back into the case, as by the action of the key.

any of several types of strong fastening rods, pins, or screws, usually threaded to receive a nut.

a sudden dash, run, flight, or escape.

a sudden desertion from a meeting, political party, social movement, etc.

a length of woven goods, esp. as it comes on a roll from the loom.

a roll of wallpaper.

Bookbinding . the three edges of a folded sheet that must be cut so that the leaves can be opened.

a rod, bar, or plate that closes the breech of a breechloading rifle, esp. a sliding rod or bar that shoves a cartridge into the firing chamber as it closes the breech.

a jet of water, molten glass, etc.

an arrow, esp. a short, heavy one for a crossbow.

a shaft of lightning; thunderbolt.

a length of timber to be cut into smaller pieces.

a slice from a log, as a short, round piece of wood used for a chopping block.

to fasten with or as with a bolt.

to discontinue support of or participation in; break with

to bolt a political party.

to shoot or discharge (a missile), as from a crossbow or catapult.

to utter hastily; say impulsively; blurt out.

to swallow (one's food or drink) hurriedly

She bolted her breakfast and ran to school.

to make (cloth, wallpaper, etc.) into bolts.

Fox Hunting . (of hounds) to force (a fox) into the open.

to make a sudden, swift dash, run, flight, or escape; spring away suddenly

The rabbit bolted into its burrow.

to break away, as from one's political party.

to eat hurriedly or without chewing.

Horticulture . to produce flowers or seeds prematurely.

Archaic . with sudden meeting or collision; suddenly. ?

bolt from the blue

a sudden and entirely unforeseen event

His decision to leave college was a bolt from the blue for his parents. Also, bolt out of the blue.

bolt upright

stiffly upright; rigidly straight

The explosive sound caused him to sit bolt upright in his chair.

shoot one's bolt

Informal . to make an exhaustive effort or expenditure

The lawyer shot his bolt the first day of the trial and had little to say thereafter.