what

determiner

1. interrogative Which, especially which of an open-ended set of possibilities. What colour are you going to use?
2. indirect, interrogative Which. I wonder what colour he is going to use.
3. relative Any ... that; all ... that; whatever. He seems to have lost what sense he had.
4. Emphasises that something is noteworthy or remarkable in quality or degree, in either a good or bad way; may be used in combination with certain other determiners, especially 'a', less often 'some'. This shows what beauty there is in nature.
5. Used to form exclamations indicating that something is remarkable, in either a good or bad way. What nonsense!

pronoun

1. interrogative Which thing, event, circumstance, etc.: used in asking for the specification of an identity, quantity, quality, etc. Hammer in that nail —What with? I didn't bring my set of tools.
2. That which; those that; the thing(s) that. He knows what he wants and what to do to get it.
3. Anything that; all that; whatever. I will do what I can to help you.
4. dialectal, nonstandard, relative That; which; who. Look! It's that bloke again what was 'ere yesterday!

adverb

1. interrogative, not comparable In what way; to what extent. What does it matter?
2. not comparable Used before a prepositional phrase to emphasise that something is taken into consideration as a cause or reason; usually used in combination with 'with' (see what with), and much less commonly with other prepositions. In short; what by the indiscretion of people here, what by the rebound which came often back from London, what by the private interests and ambitious views of persons in the French court, and what by other causes unnecessary to be examined now, the most private transactions came to light [...]

interjection wha · wat

1. An expression of surprise or disbelief. What! That’s amazing!
2. What do you want? An abrupt, usually unfriendly enquiry as to what a person desires. What? I'm busy.
3. UK, abbreviation, clipping, colloquial, dated Clipping of what do you say?, used as a type of tag question to emphasise a statement and invite agreement, often rhetorically.what do you say? It’s a nice day, what?
4. What did you say? I beg your pardon? This usage is often considered impolite, with the more polite "Pardon?" or "Excuse me?" preferred. — Could I have some of those aarrrrrr mmmm ... — What?
5. Indicating a guess or approximation, or a pause to try to recall information. I must have been, what, about five years old.

Similar: what-what, wot, pardon

noun whats

1. obsolete, uncountable Something; thing; stuff. They prayd him sit, and gave him for to feed / Such homely what as serves the simple clowne, / That doth despise the dainties of the towne[…]
2. countable The identity of a thing, as an answer to a question of what. The emphasis on the interplay between the hows and whats of interpretive practice is paramount.
3. countable Something that is addressed by what, as opposed to a person, addressed by who. 2012, "We Are Both", season 2, episode 2 of Once Upon a Time Regina: What are you? Rumplestiltskin: What? What? What? My, my, what a rude question! I am not a what.

particle

1. Manglish, Singlish Emphasizes the truth of an assertion made to contradict an evidently false assumption held by the listener. Pitch contour: low [wʌt˩], low-dipping [wʌt˨˩]
2. Manglish, Singlish Used to invite agreement or acknowledgment when something is assumed to be straightforward or already obvious to begin with; similar in function to “right?” and “as you know”. Pitch contour: low [wʌt˩], low-dipping [wʌt˨˩]
3. Manglish, Singlish Used after a direct assertion to reinforce a disagreeing opinion. Pitch contour: low [wʌt˩], low-dipping [wʌt˨˩]