Real Dictionary

bolt
countable noun: A bolt is a long metal object which screws into a nut and is used to fasten things together.
verb: When you bolt one thing to another, you fasten them firmly together, using a bolt.

bolt in American English 1
a short, heavy, often blunt arrow shot from a crossbow
to dash out suddenly; spring; dart
to shoot (an arrow, etc.)
noun: a movable bar or rod that when slid into a socket fastens a door, gate, etc.

bolt in American English 2
to sift (flour, grain, etc.) so as to separate and grade
transitive verb: to sift through a cloth or sieve

Bolt in British English
noun: Robert (Oxton). 1924–95, British playwright. His plays include A Man for All Seasons (1960) and he also wrote a number of screenplays

bolt in British English 1
noun: a bar that can be slid into a socket to lock a door, gate, etc

bolt in British English 2
to pass (flour, a powder, etc) through a sieve

bolt in Mechanical Engineering
noun: A bolt is a pin with parallel threads and a flat end, used for fastening parts together and often secured with a nut.