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Common Idioms and Phrases > D-Letter Sayings - Meanings and Origins of Phrases
Note: Tracking the origins for the majority of common phrases and sayings isn't easy, in fact, it's often impossible. Usually what you will find are plausible theories that try to explain a phrase's origin, but remember, they are just theories.

The quotes on this website come from older books, poems, newspapers, etc. They can be used as an indicator to determine how old some sayings are. Keep in mind, however, that if a saying is being used in an old newspaper, it's probably already well-known, so it's likely older than that.
Origins for the idiom Drop Like Flies.
There are a vast variety of nuts out there in the world to choose from. Yes, peanuts, walnuts, 
hazelnuts, chestnuts, cashews, almonds, and the list goes on. These nuts, among others, are just a few types found in the diets of many people today. To note, some might say that a few of the things I listed are considered to be tree seeds, but most people probably recognize them as nuts, so I'll just call them by that name.

Anyways, according to the website Word-Detective, by the mid to late-1800s, the word "nut" was slang to mean a person's head. Not long after, it looks like it also acquired the meaning of someone who was not acting right in the head, e.g., a person acting strange might be described as "nuts" or being "off their nut." 

An early example of this phrase can be seen written in The Bilioxi Daily Herald, a newspaper printed in 1884. The idiom is written under an advice column, where people could write in asking a woman named Ann Landers for advice:

"DEAR ANN LANDERS: I am a boy, 18 years old, a high school senior, and my dad is driving me nuts! 
He has read a lot about drugs and is scared to death I might be trying something."

Referencesnewspaperarchive contained a copy of the newspaper with the saying in the quote above.
To be greatly frustrated or annoyed. The word "nuts" is sometimes replaced by the words crazy, bonkers, bananas, insane, or up the wall. However, the meaning remains unchanged.

When people are annoyed to the point where they can no longer tolerate anymore, they might use this common idiom to describe their frustrations.
* The loud music my neighbor is playing is really driving me nuts, and if he doesn't stop soon, I'm going over there to give him a piece of my mind!

* Emily is driving herself nuts over the job interview she has tomorrow, and is having trouble sleeping from the anxiety. 
The meaning of the phrase Dropping Like Flies.

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