through

Through is defined as in at one side or end and out at another.

(preposition)

An example of through is a train traveling the distance of a tunnel.

Through means completely or to the end.

(adverb)

An example of through is to see a plan all the way from its conception to its execution.

See through in Webster's New World College Dictionary

in one side and out the other side of; from end to end of
1. in the midst of: flying through the clouds
2. among: hiking through the trees
by way of: a train that goes through Boston
over the entire extent or surface of
to various places in; around: touring through France
1. from the beginning to the end or conclusion of: to go through an experience, through the summer, went through all his provisions
2. ☆ up to and including: through Friday
without making a stop for: to go through a red light
past the limitations or difficulties of: to fight through all the red tape
by means of: through her help
as a result of; because of: done through error

Origin: ME thurgh, thrugh < OE thurh, akin to Ger durch < IE base *ter-, through, beyond > L trans, across, Sans tiráḥ, through

adverb

in one side and out the other; from end to end
from the beginning to the end
completely to the end; to a conclusion: to see something through
in every part or way; thoroughly; completely: soaked through
also through and through

adjective

extending from one place to another; allowing free passage: a through street
☆
1. traveling to the destination without stops: a through train
2. continuing on without making a stop: through traffic
☆ not necessitating changes; good for traveling without intermediate transfer: a through ticket
arrived at the end; finished: through with an assignment
at the end of one's usefulness, resources, etc.: through in politics
having no further dealings, connections, etc. (with someone or something)

See through in American Heritage Dictionary 4

preposition

In one side and out the opposite or another side of: went through the tunnel.
Among or between; in the midst of: a walk through the flowers.
By way of: climbed in through the window.
a. By the means or agency of: bought the antique vase through a dealer.
b. Into and out of the handling, care, processing, modification, or consideration of: Her application went through our office. Run the figures through the computer.
Here and there in; around: a tour through France.
From the beginning to the end of: stayed up through the night.
At or to the end of; done or finished with, especially successfully: We are through the initial testing period.
Up to and including: a play that runs through December; a volume that covers A through D.
Past and without stopping for: drove through a red light.
Because of; on account of: She succeeded through hard work. He declined the honor through modesty.

adverb

From one end or side to another or an opposite end or side: opened the door and went through.
From beginning to end; completely: I read the article once through.
Throughout the whole extent or thickness; thoroughly: warmed the leftovers clear through; got soaked through in the rain; a letter that was shot through with the writer's personality.
Over the total distance; all the way: drove through to their final destination.
To a conclusion or an accomplishment: see a matter through.

adjective

Allowing continuous passage; unobstructed: a through street.
a. Affording transportation to a destination with few or no stops and no transfers: a through bus; a through ticket.
b. Continuing on a highway without exiting: through traffic; through lanes.
Passing or extending from one end, side, or surface to another: a through beam.
Having finished; at completion: She was through with the project.
Having no further concern, dealings, or connection: I'm through with him.
a. Having no more use, value, or potential; washed-up: That swimmer is through as an athlete.
b. Doomed to death or destruction.