Merriam-Webster Collegiate Dictionary - what

 I. pronoun  Etymology: Middle English, from Old English hw?t, neuter of hwa who — more at who  Date: before 12th century  1.  a.  (1) — used as an interrogative expressing inquiry about the identity, nature, or value of an object or matter ~ is this ~ is wealth without friends ~ does he earn ~ hath God wrought  (2) — often used to ask for repetition of an utterance or part of an utterance not properly heard or understood you said ~  b.  (1) archaic who 1 — used as an interrogative expressing inquiry about the identity of a person  (2) — used as an interrogative expressing inquiry about the character, nature, occupation, position, or role of a person ~ do you think I am, a fool ~ is she, that all our swains commend her — Shakespeare  c. — used as an exclamation expressing surprise or excitement and frequently introducing a question ~, no breakfast  d. — used in expressions directing attention to a statement that the speaker is about to make you know ~  e.  (1) — used at the end of a question to express inquiry about additional possibilities is it raining, or snowing, or ~  (2) — used with or at the end of a question usually in expectation of agreement is this exciting, or ~  f. chiefly British — used at the end of an utterance as a form of tag question a clever play, ~  2. chiefly dialect that IV,1, which 3, who 3  3.  a. that which ; the one or ones that no income but ~ he gets from his writings — sometimes used in reference to a clause or phrase that is yet to come or is not yet complete gave also, ~ is more valuable, understanding  b. the thing or things that ~ you need is a vacation ~ angered us was the tone of the article  4.  a. ~ever 1a say ~ you will  b. obsolete whoever  II. adverb  Date: before 12th century  1. obsolete why  2. in ~ respect ; how ~ does he care  3. — used to introduce prepositional phrases in parallel construction or a prepositional phrase that expresses cause and usually has more than one object; used principally before phrases beginning with with ~ with unemployment increasing ~ with the war, ~ with the sweat, ~ with the gallows, and ~ with poverty, I am custom-shrunk — Shakespeare  III. adjective  Date: 13th century  1.  a. — used as an interrogative expressing inquiry about the identity, nature, or value of a person, object, or matter ~ minerals do we export  b. how remarkable or striking for good or bad qualities — used especially in exclamatory utterances and dependent clauses ~ mountains remember ~ fun we had ~ a suggestion ~ a charming girl  2.  a.  (1) ~ever 1a  (2) any ornament of ~ description soever  b. the…that ; as much or as many…as rescued ~ survivors they found