There are screws everywhere, so where's the very nearest one to you?
My keyboard is probably held together with them, but I can't see one as I type, so the nearest screw I can see is...
...holding my desk-fan together. The physically nearest screws, though, are stopping my glasses falling apart. Some of us might even have screws in our teeth, or in our joints.
Civilisation is held together with screws...
...which might be the reason why so much of the time things are screwed up.
A shot in billiards that has some backspin on it is a screw; a propeller can be called a screw; a prison guard can be called a screw (though not if one is listening).
A screw is a basic wage, and so is anything held in a twist of paper. It's a broken-down horse:
If you have a screw loose then you're bonkers; if you have your head screwed on the right way then you are likely to be successful.
And where did the word come from?
The most completely enchanting source you could possibly imagine.
Spot the Frippet: screw. This word appeared in English in the 1400s and comes from the French word escroe, from the Latin scrōfa, which means sow, almost certainly because a pig's curly tail is like the thread of a screw.