Etymology

Pronoun

1. which thing, event, circumstance, etc.: used interrogatively in asking for the specification of an identity, quantity, quality, etc.

   What is your address?

   You told them what?

   (UK) (colloquial) It's rather late, what?

2. that; which
   • 1902, J. M. Barrie, The Admirable Crichton

     That’s her; that’s the thing what has stole his heart from me.

1. in some manner or degree; in part; partly; usually followed by with.

   What with singing and joking, the time passed quickly.

2. Such; this is; that is.

   What a pity.

   What a beautiful day!

3. Why?
4. Used to introduce each of two coordinate phrases or concepts; both...and.
   • 1485, Sir Thomas Malory, Le Morte Darthur, Book III:

     and so they rode fresshly with grete royalte, what by water and what by land, tyl that they came nyghe vnto london.

Conjunction

1. that which; those which; the thing that

   He knows what he wants.

Interjection

1. an expression of surprise or disbelief.

   What! That’s amazing.

2. (UK) (colloquial) is that not true?

   It’s a nice day, what? (sometimes repeated, e.g.: What-what?)

3. (UK) (colloquial) greeting (archaic).

   What ho, Frobisher!

1. which; which kind of.

   What shirt are you going to wear?

   What time is it?

   What kind of car is that?

2. how much; how great (used in an exclamation)

   What talent he has!

   What a talent!