It means really intelligent. A razor is very sharp, so a razor-sharp wit would be a sharp wit, or a smart brain.
You can also see this used to refer to someone who is sarcastic, with the meaning "sharp" referring to "cutting" as in slightly mean.
Someone who is quick to come back with a witty, smart, or brilliant answer.
It means complete and total frustration with a situation.
Sorry, there is no such idiom as "at wit's put end to". "at wit's end" means you have tried every possible way to solve a problem but cannot do it and do not know what to do next. "put and end to" means to stop or put a stop to something.
It's not really an idiom. It means "what are you thinking about."
RFP is not an idiom. It's an abbreviation.
It is not an idiom, it means your nose is itching.
idiom means expression like a page in a book
It's not an idiom. It means the tip of your nostril.
"Sieve" is not an idiom. See the related link.
This is not an idiom. It is a measurement. $100,000 is how you write it in numbers.
Simply its mean a bully.
The idiom your blood is boiling usually means that you are mad/furious.