1
- a large metal pin, in particular大金属栓, 尤指：
1.1
- a bar that slides into a socket to fasten a door or window（门、窗的）插销。
1.2
- a long pin with a head that screws into a nut or is used to fasten things together螺栓。
1.3
- the sliding piece of the breech mechanism of a rifle枪栓。
1.4
- Climbing a long pin that is driven into a rock face so that a rope can be attached to it【登山】岩石栓。
2
- a short, heavy arrow shot from a crossbow（用弩弓发射的）弩箭。
3
- a flash of lightning that can be seen shooting across the sky in a jagged white line闪电, 霹雳。
with obj.
1- fasten with a bolt, in particular拴住, 扣紧, 尤指：
1.1
- fasten (a door or window) with a bar that slides into a socket将门（或窗）闩上：
all the doors were locked and bolted.
所有的门都已经锁好闩上了。
1.2
- (with obj. and adverbial of place) fasten (something) to something else with a long pin that screws into a nut用螺栓固定（某物）。
短语
a bolt from（或out of）the blue
- a sudden and unexpected event or piece of news意外事件（或消息）：
the job came like a bolt from the blue.
得到这份工作是出乎预料的事。
ORIGIN: with reference to the unlikelihood of a thunderbolt coming from a clear blue sky.
bolt upright
- with the back very straight笔直：
she sat bolt upright in bed.
她笔直地坐在床上。
have shot one's bolt
- informal have done all that is in one's power〈非正式〉竭尽全力。
词源
Old English, 'arrow', of unknown origin; related to Dutch bout and German Bolzen 'arrow, bolt for a door'.
1
- no obj.(of a horse or of other animal) run away suddenly out of control（马或其他动物）突然失控逃跑：
the horses shied and bolted.
马受惊挣脱了缰绳。
1.1
- no obj., with adverbial of direction(of a person) move or run away suddenly in an attempt to escape（人）逃跑：
they bolted down the stairs.
他们逃下楼梯。
1.2
- with obj.(in hunting) cause (a rabbit or fox) to run out of its burrow or hole逼迫（兔子、狐狸）跑出洞穴。
1.3
- (of a plant) grow quickly upwards and stop flowering as seeds develop（植物）迅速成长结籽而不再开花：
the lettuces have bolted.
莴苣已经结籽了。
2
- with obj. eat or swallow (food) quickly匆匆吞下（食物）：
it is normal for puppies to bolt down their food.
小狗囫囵吞下食物是常事。
短语
make a bolt for
- try to escape by moving suddenly towards (something)试图迅速逃到（某处）：
Ellie made a bolt for the door.
埃利往门口逃去。
词源
Middle English: from BOLT1 , expressing the sense 'fly like an arrow'.
1
- a roll of fabric, originally as a measure（布的）一匹：
the room is stacked with bolts of cloth.
房间里堆满了布匹。
2
- a folded edge of a piece of paper that is trimmed off to allow it to be opened, as on a section of book（纸等的）卷边。
词源
Middle English: transferred use of BOLT1 .