Definition of: what

(hwot, hwut) adjective
1. In interrogative construction, asking for information that will specify the person or thing qualified by it: Of what person do you speak?
2. How surprising, ridiculous, great, or the like: used in exclamation to express excess or something exceptional in the person or thing qualified: commendatory or the reverse according to circumstances: What genius! What a noise that boy is making!
3. How much: an ambiguous use: What cash has he?
—pron.
1. Which circumstance, event, relation, or the like: asking for some specification concerning persons or things referred to: an interrogative pronoun used in absolute interrogation: Who and what is he? When used of persons, it ordinarily implies some shade of contempt. In this sense what is used elliptically for “What did you say?” or in surprise or indignation: What! did he really say that? Formerly it was used as a common introductory expletive like well, especially in a summons, as in the phrase what ho!
2. That which: a double relative, equivalent to a demonstrative followed by a simple relative: Tell me what it is; What followed occupied little time.
3. Dial. or Illit. That or which: a simple relative: a donkey what wouldn't go.
—what for
1. Why: What did you do that for?
2. Slang Physical punishment or verbal rebuke: He took the bully outside and gave him the what for.
—adverb
1. In what respect; to what extent: What are you profited?
2. In some measure; partly: usually followed by with: What with the heat, and what with the noise, it is distracting.
3. For what reason; why.
4. How extraordinarily! how!: an exclamatory or intensive use.
—conj.
1. So far as; as well as: He did what he could at the time.
2. That: especially in the phrase but what. [OE hwæt, neut. of hwa who]