how adverb [OE. how, hou, hu, hwu, AS. h, from the same root as hwā, hwæt, who, what, pron. interrog.; akin to OS. hwōw, D. hoe, cf. G. wie how, Goth. hwē wherewith, hwaiwa how. √182. See Who, and cf. Why.]

1. In what manner or way; by what means or process.

How can a man be born when he is old? John iii. 4.

2. To what degree or extent, number or amount; in what proportion; by what measure or quality.

O, how love I thy law! it is my meditation all the day. Ps. cxix. 97.

By how much they would diminish the present extent of the sea, so much they would impair the fertility, and fountains, and rivers of the earth. Bentley.

3. For what reason; from what cause.

How now, my love! why is your cheek so pale? Shak.

4. In what state, condition, or plight.

How, and with what reproach, shall I return? Dryden.

5. By what name, designation, or title.

How art thou called? Shak.

6. At what price; how dear. [Obs.]

How a score of ewes now? Shak.

☞ How is used in each sense, interrogatively, interjectionally, and relatively; it is also often employed to emphasize an interrogation or exclamation.

“How are the mighty fallen!” 2 Sam. i. 27.

Sometimes, also, it is used as a noun; – as,

the how, the when, the wherefore. Shelley.

Let me beg you – don’t say “How?” for “What?” Holmes.

-- Webster's unabridged 1913