what the devil

pronoun

1. the nature, class, name, purpose, etc. of a thing: what is that object?what is your address?
   1. an explanation or repetition of something previously said: you told them what?
   2. such an explanation or repetition: used elliptically: “Sh. Quiet!”“What?”
   a quantity, sum, etc.: what will it cost? the value, importance, or effect of something: what is life without music?
2. that which or those which: to know what one wants anything that: do what you will the exact person or thing that: he's not what he was five years ago that or who: a nonstandard usage: the man what gave it to me
4. Chiefly Brit., Informal used to end a sentence with a general or rhetorical interrogative force: it's rather late, what? used to introduce a parenthetical element in a sentence: she has, what is rare, true tolerance used elliptically to mean “what it is,” “what to do,” etc.: I'll tell you what!

noun

adjective

1. which or which kind of: used interrogatively or relatively in asking for or specifying the nature, identity, etc. of a person or thing: what man told you that? he knows what role she played
2. as much, or as many, as: take what time (or men) you need
3. how great, surprising, magnificent, disappointing, etc.: in exclamations: what a man! what nonsense!

adverb

1. in what respect? to what degree? how?: what does it matter?
2. how greatly, surprisingly, etc.: in exclamations: what tragic news!
3. Obsolete why?

conjunction

interjection