through

UK: /ˈθruː/ US: /θru/ ,(thro̅o̅)

WordReference Random House Learner's Dictionary of American English © 2026

through /θru/   prep. 

1. in at one end, side, or surface and out at the other:
   to pass through a tunnel.
2. past;
   beyond:
   drove through a red light.
3. from one to the other of:
   monkeys swinging through the trees.
4. across the extent of:
   traveled through Europe.
5. during the whole period of;
   throughout:
   We worked through the night.
6. done with:
   What time are you through work?
7. to and including:
   He lived there from 1935 through 1950.
8. by means of:
   I found out through him.
9. from the first to the final stage of:
   Somehow he managed to get through the entire performance.

adv. 

10. in at one end, side, or surface and out at the other:
    to push a needle through.
11. all the way:
    This train goes through to Boston.
12. throughout, completely:
    She was soaked through.
13. from beginning to end:
    read the letter all the way through.
14. to completion:
    to see it through.

adj. 

15. Pronouns at a point or in a state of completion of an action, etc.;
    finished:
    [be + ~] Please be quiet until I'm through.
16. at the end of all relations or dealings:
    [be + ~ (+ with)] She had to tell her boyfriend they were through.
17. extending or going from one end, etc., to the other:
    a through road.
18. proceeding to a destination, etc., without a change, break, or deviation:
    [before a noun] a through flight.
19. of no further use or value;
    washed-up;
    finished:
    [be + ~] Critics say he's through as a writer.

Idioms

20. Idioms through and through:
    • throughout every part;
      thoroughly:
      I was cold through and through.
    • in all respects:
      She is an aristocrat through and through.

WordReference Random House Unabridged Dictionary of American English © 2026

through  (thro̅o̅), prep. 

1. in at one end, side, or surface and out at the other:
   to pass through a tunnel; We drove through Denver without stopping. Sun came through the window.
2. past;
   beyond:
   to go through a stop sign without stopping.
3. from one to the other of;
   between or among the individual members or parts of:
   to swing through the trees; This book has passed through many hands.
4. over the surface of, by way of, or within the limits or medium of:
   to travel through a country; to fly through the air.
5. during the whole period of;
   throughout:
   They worked through the night.
6. having reached the end of;
   done with:
   to be through one's work.
7. to and including:
   from 1900 through 1950.
8. by the means or instrumentality of;
   by the way or agency of:
   It was through him they found out.
9. by reason of or in consequence of:
   to run away through fear.
10. in at the first step of a process, treatment, or method of handling, passing through subsequent steps or stages in order, and finished, accepted, or out of the last step or stage:
    The body of a car passes through 147 stages on the production line. The new tax bill finally got through Congress.

adv. 

11. in at one end, side, or surface and out at the other:
    to push a needle through; just passing through.
12. all the way;
    along the whole distance:
    This train goes through to Boston.
13. throughout:
    soaking wet through.
14. from the beginning to the end:
    to read a letter through.
15. to the end:
    to carry a matter through.
16. to a favorable or successful conclusion:
    He barely managed to pull through.
17. through and through:
    • through the whole extent of;
      thoroughly:
      cold through and through.
    • from beginning to end;
      in all respects:
      an aristocrat through and through.

adj. 

18. Pronouns having completed an action, process, etc.;
    finished:
    Please be still until I'm through. When will you be through with school?
19. at the end of all relations or dealings:
    My sister insists she's through with selfish friends.
20. passing or extending from one end, side, or surface to the other.
21. traveling or moving to a destination without changing of trains, planes, etc.:
    a through flight.
22. (of a road, route, way, course, etc., or of a ticket, routing order, etc.) admitting continuous or direct passage;
    having no interruption, obstruction, or hindrance:
    a through highway; through ticket.
23. Civil Engineering (of a bridge truss) having a deck or decks within the depth of the structure. Cf. deck (def. 21).
24. of no further use or value;
    washed-up:
    Critics say he's through as a writer.

• bef. 900; Middle English (preposition and adverb, adverbial), metathetic variant of thourgh, Old English thurh, cognate with German durch; akin to Old English therh, Gothic thairh through, Old High German derh perforated, Old English thyrel full of holes (adjective, adjectival), hole (noun, nominal). See thirl

Synonyms

• 8. See by. 

Collins Concise English Dictionary © HarperCollins Publishers::

through / θruː/ preposition

1. going in or starting at one side and coming out or stopping at the other side of: a path through the wood
2. occupying or visiting several points scattered around in (an area)
3. as a result of; by means of
4. up to and including: Monday through Friday
5. during: through the night
6. at the end of; having (esp successfully) completed
7. through with ⇒ having finished with (esp when dissatisfied with)

adjective

1. (postpositive) having successfully completed some specified activity
2. (on a telephone line) connected
3. (postpositive) no longer able to function successfully in some specified capacity: as a journalist, you're through
4. (prenominal) (of a route, journey, etc) continuous or unbroken: a through train

adverb

1. through some specified thing, place, or period of time
2. thoroughly; completely

Etymology: Old English thurh; related to Old Frisian thruch, Old Saxon thuru, Old High German duruh

WordReference Random House Learner's Dictionary of American English © 2026

thru /θru/   prep., adv., adj. 

1. an informal, simplified spelling of through.

WordReference Random House Unabridged Dictionary of American English © 2026

thru (thro̅o̅), prep., adv., adj. 

1. an informal, simplified spelling of through.