might

1 /maIt/ modal verb negative short form mightn't

1 if something might happen or might be true, there is a possibility that it may happen or be true but you are not certain: Who knows - England might win the next World Cup! | "Are you going to write her a letter?" "I might, I might not." | You might not have noticed but I've put up a 'no smoking' sign in here. | Did you see the way he was driving? I might have been killed.

2 the past tense of may: Thinking it might rain, I decided to go in the car. | She asked if she might open a window.

3 used to give advice or make a suggestion: If the police can't help, you might try the Citizens Advice Bureau. | I thought we might spend the lesson studying irregular verbs.

4

a) spoken old-fashioned used to ask politely if you can do something: Might I come in?

b) might I say/ask/add etc spoken used to politely give more information, ask a question, interrupt etc: Might I just add that Miriam has been a pleasure to work with and we wish her every success in the future.

5 used when you are angry or surprised when someone has not done something that you think they should do: You might have cleaned up before you left! | Don't you think he might at least say thank you?

6 I might have known/guessed etc spoken used to say that you are not surprised at a situation: Jake Thompson! I might have known you'd be behind all this!

7 might well if something might well happen or might well be true you think it is fairly likely to happen or be true: You might well find that you'll need more by the weekend.

8 might (just) as well usually spoken used to suggest doing something that you do not really want to do, because you have no better ideas: It's no good waiting for the bus. We might as well walk.

9 might...but... used to tell someone that although what they said is true, something else which seemed very different is also a fact: You might be a strong swimmer but that doesn't mean you can win a triathlon.

10 formal used to say why something happens or the reason why someone does something: Samuel left his children a letter, so that his family might understand why he had to go away.

11 old-fashioned humorous used to politely ask for information: And who might you be, young man?

—compare may 1 2 noun (U)

1 great strength and power: the full might of the Russian army | with all your might (=using all your strength and a lot of effort): He swung the ax with all his might. | with might and main literary (=with a lot of strength)

2 might is right BrE might makes right AmE used to say that powerful people and countries can do whatever they want