a bolt from the blue Definition

bolt¹
noun

1. A bar or rod that slides into a hole or socket to fasten a door or gate, etc.
2. A small thick round bar of metal, with a screw thread, used with a nut to fasten things together.
3. A sudden movement or dash away, especially to escape from someone or something.

Example: make a bolt for it
4. A flash of lightning.

Thesaurus: lightning, flash, stroke, shock, thunderbolt.
5. A short arrow fired from a crossbow.
6. A roll of cloth.

verb bolted, bolting

1. To fasten (a door or window, etc) with a bolt.

Thesaurus: secure, lock, latch, fasten, fetter, bar.
2. To fasten together with bolts.
3. To eat (a meal, etc) very quickly.

Thesaurus: devour, gobble, gorge, gulp, wolf, guzzle, stuff, cram.
intr
4. To run or dash away suddenly and quickly.

Thesaurus: flee, escape, run, dash, sprint, fly, abscond.
intr
5. Said of a horse: to run away out of control.
intr
6. Said of a plant: to flower and produce seeds too early, usually in response to low temperatures.
7. bot.
Said of a biennial: to behave like an annual.

Idiom: a bolt from the blue

A sudden, completely unexpected and usually unpleasant, event.

Idiom: bolt upright

Absolutely straight and stiff.

Idiom: have shot one's bolt

To have made a last attempt to do something but to have failed.

Etymology: 17c: like an archer who has only one bolt or arrow and is defenceless and unable to do more once he has fired it. &clock; Anglo-Saxon.