The Collaborative International Dictionary of English v.0.48:
How \How\, adv. [OE. how, hou, hu, hwu, AS. h?, from the same
root as hw[=a], hw[ae]t, who, what, pron. interrog.; akin to
OS. hw[=o]w, D. hoe, cf. G. wie how, Goth. hw[=e] wherewith,
hwaiwa how. [root]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.
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?
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.
Note: 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?"