It was a feature song in the musical Cry Baby.

It reminded me of a few people I have met over the years. I can’t name them, because some are still my friends, or at least acquaintances.

As early as 1834 the expression loose screw was used to illustrate a flaw in state affairs. In Martin Chuzzlewit, Charles Dickens wrote “I see well enough there’s a screw loose in your affairs”.

But the word was used well before that. For instance, in 1810 Sporting Magazine said “the others had got a screw loose”. I don’t know what the magazine meant by that.

My opinion is that as the years progressed the meaning of “something wrong” gave way gradually to something wrong in a person’s head, without being too critical.

Now, whenever we say Bill has a screw loose we mean we don’t agree with his line of thinking. Of course, Bill might be correct and maybe we should take a close look at ourselves. We might not be the sharpest tool in the shed, as a local hardware store keeps telling us.

The expression isn’t meant to be too condemning. It says about the person it is aimed at that he or she is eccentric or a bit neurotic, without going too far.

In the very early days screw came from the Latin to mean a female pig, possibly because of the corkscrew tail, and has had a few meanings since then, some unsavoury 

The word screw has many meanings, applied to billiards, cricket and rowing and a few slang words in Australia. This country only seems to have the slang words.

If you want some other words to explain your friends, you could try a sandwich short of a picnic, bats in the belfry, cockeyed, crackpot, out in the sun too long, round the bend and a few other words I could list but decline to do so in case they get me into trouble.

But be careful how you use them. Remember that some people don’t have a sense of humour and might just think you mean everything you say.

Then again, you might.