a question concerning the way or manner in which something is done, achieved, etc.: a child's unending whys and hows.
17.
a way or manner of doing something: to consider all the hows and wherefores.
18.
a word formerly used in communications to represent the letter H.
Idioms
19.
and how! Informal. certainly! you bet!: Am I happy? And how!
20.
Here's how, Informal. (used as a toast).
21.
how come? Informal. how is it that? why?: How come you never visit us anymore?
22.
how so? how does it happen to be so? why?: You haven't any desire to go? How so?
Origin: before 900; Middle English how, hu,Old English hū; cognate with Old Frisian hū, ho,Dutch hoe; akin to German wie (Old High German hweo), Gothic hwaiwa
Native American greeting, Siouxan (cf. Dakota hao, Omaha hau); first recorded 1817 in Eng, but noted early 17c. by Fr. missionary Jean de Brebeuf among Hurons as an expression of approval (1636).