how Definition

how
adverb

1. In what way; by what means

Example: How did it happen?
2. To what extent

Example: How old is he?
Example: How far is it?
3. In what condition, especially of health

Example: How is she feeling now?
4. To what extent or degree is something good, successful, etc

Example: How was your holiday?
5. For what cause or reason; why

Example: How can you behave like that?
6. Using whatever means are necessary.

Example: Do it how best you can

conj

1. colloq
That.
Example: He told me how he'd done it on his own
2. In which manner or condition.

Example: I don't care how you get there

noun

1. A manner or means of doing something.

Example: The hows and whys of it

Idiom: and how!

(riginally N Amer)
colloq
Very much indeed; definitely.

Idiom: how about ...

Would you like ... what do you think of ...
Example: How about another piece of cake?
Example: How about going to see a film?

Idiom: how are you?

A conventional greeting to someone, sometimes referring specifically to their state of health.

Idiom: how come?

colloq
For what reason? how does that come about?
Example: How come you're not going tomorrow?

Idiom: how do you do?

A formal greeting to a person one is meeting for the first time.

Idiom: how now (how so?)

What is this? how is this so?

Idiom: how's that? (howzat)

What is your opinion of that?

An appeal to the umpire to give the batsman out.

Idiom: how's your father

Amorous play; sexual intercourse.

Ridiculous or foolish activity; nonsense.

Idiom: the how and why

The method, or manner, and the cause.

Etymology: Anglo-Saxon hu, probably an adverbial form of hwa who.