Longman Dictionary of Contemporary English - by

~1 prep 1 used especially with a passive1 (2) v to show the person or thing that does something or makes something happen  (I was attacked by a dog. | The building was designed by a famous architect. | We are all alarmed by the rise in violent crime.) 2 using or doing a particular thing  (You can reserve the tickets by phone. | Send it by airmail. | I know her by sight. (=recognize her face) | by doing sth)  (She earns her living by selling insurance. | by train/plane/car)  (We're travelling to London by train.) 3 passing through or along a particular place  (They came in by the back door. | It's quicker to go by the country route.) 4 beside or near something  (She stood by the window looking out over the fields. | Jane went and sat by Patrick.) 5 if you move or travel by someone or something, you go past them without stopping  (He walked by without noticing me. | I go by the Vicarage every day on my way to work.) 6 used to show the name of someone who wrote a book, produced a film, wrote a piece of music etc  (the `New World Symphony' by Dvorak) 7 not later than a particular time date etc  (The documents need to be ready by next Friday. | I reckon the film should be over by 9.30.) 8 according to a particular rule, method, or way of doing things  (You've got to play by the rules. | Profits were $6 million, but by their standards this is low.) 9 used to show the amount or degree of something  (The price of oil fell by a further $2 a barrel. | I was overcharged by $3. | by far (=by a large amount or degree))  (Godard's first film was better by far.) 10 used to show the part of a piece of equipment or of someone's body that someone takes or holds  (He took her by the arm and led her across the road. | She grabbed the hammer by the handle.) 11 used when expressing strong feelings or making serious promises  (By God, I'll kill that boy when I see him!) 12 used between two numbers that you are multiplying or dividing  (What's 48 divided by 4?) 13 used when giving the measurements of a room, container etc  (a room 15 metres by 23 metres) 14 used to show a rate or quantity  (We're paid by the hour.) 15 day by day/bit by bit etc used to show the way in which something happens  (Day by day he grew weaker.) 16 used to show the situation or period of time during which you do something or something happens  (You could ruin your eyes reading by torchlight. | by day/night)  (a tour of Paris by night) 17 used to show the connection between one fact or thing and another  (Colette's French by birth. | It's fine by me if you want to go.) 18 as a result of an action or situation  (by accident)  (I saw Maureen quite by accident in the supermarket the other day. | by mistake)  (I managed to delete an afternoon's work on the computer by mistake.) 19 if a woman has children by a particular man, that man is the children's father  (Ann's got two children by her previous husband.) 20 (all) by yourself completely alone  (Dave spent Christmas all by himself.) ~2 adv 1 if someone or something moves or goes by, they go past  (As I was standing on the platform the Liverpool train went whizzing by. | Ten years had gone by since I had last seen Marilyn. | James walked by without even looking in my direction.) 2 beside or near someone or something  (A crowd of people were standing by waiting for an announcement.) 3 put/keep/lay sth by etc to put something somewhere in order to use it in the future  (Her mother gave her a dinner service to put by for when she got married.) 4 call/stop/go by to go to someone's house in order to visit them for a short time  (Why don't you stop by for a drink after work?) 5 by and large especially spoken used when talking generally about someone or something  (Charities are, by and large, exempt from income tax.) 6 by the by spoken used when mentioning something that may be interesting but is not particularly important  (By the by, Ian said he might call round tonight.) 7 by and by especially literary soon