He doesn't mince words off the top of his head

Today is our regular look-at-language spot, conducted by Professor Wordsmith.

Yes, people today are becoming more and more interested in matters linguistic. And what does that mean? It means that more and more people with a hitherto useless English degree can now earn a living writing useless columns in newspapers about words!

One such man is Professor Wordsmith, who is here with us today to answer your pointless questions about the derivations of English words. Take it away, Prof ...

Hello, Professor. I just wanted to know what was the derivation of the expression "off the top of my head". When people say that they are talking off the top of their head, it means that they are talking without notes, without script, unprepared, but I don't see what the top of the head has to do with it.

Professor Wordsmith writes: It's because we don't wear hats any more.

Pardon?

Professor Wordsmith writes: When someone was talking a lot of gibberish or unprepared nonsense we used to say that he was talking through his hat. Nowadays people don't wear hats nearly as much as they used to, so the expression has lost its force. Unwilling to lose it, we have changed it to "off the top of my head", because that is where the hat used to be. Next!

Where does the expression "a barrel of laughs" come from? Why do we say that someone is a barrel of laughs? I can't see the connection between barrels and laughter.

Professor Wordsmith writes: Well, in the old days of the music hall, before they had microphones and television and canned laughter and all that, it was very difficult for a nervous comedian to build up an atmosphere in those huge music halls. So what they did was have several stagehands backstage leading the laughter and the applause, which they did by literally getting into barrels and laughing inside them so that the laughter was amplified. It was in fact a primitive form of canned laughter - or casked laughter, perhaps; maybe even draught laughter! Next, please.

Why do we say that someone is as thick as two short planks?

Professor Wordsmith writes: To denote that someone is stupid, stupid.

I know that. I'm just asking where the expression comes from.

Professor Wordsmith writes: Well, planks are made of wood, and wood is traditionally associated with stupidity.

Oh, come on! You can do better than that! Why should a short plank be any thicker than a long plank? Why not say three short planks? Why not say "as thick as a tree"? Come on, Professor, tell us that!

Professor Wordsmith writes: OK, wise guy. Two short planks is actually Cockney rhyming slang.

Rhyming with what?

Professor Wordsmith writes: Banks.

You what?

Professor Wordsmith writes: "As thick as two short planks" is slang for "as stupid as banks".

What's so stupid about banks?

Professor Wordsmith writes: Oh, come on! Banks are notoriously stupid. They lend money to South American countries which have no intention of paying it back. They charge you pounds 20 for writing a letter. They let people like Nick Leeson make them bankrupt. They ...

OK, OK. I grant you that.

Professor Wordsmith writes: Thank you. You're very kind. Next!

Why do we say of someone that she doesn't mince her words? Why "mince"? Why don't we say that she doesn't bake, boil or fricassee her words? If there are some people who don't mince their words, are there other people who do? And what are words like when they are minced?

Professor Wordsmith writes: Well, you'll find all the necessary recipes in Delia Smith's Book of Words, published by Radio Times Cover Page Publications. But very briefly, it's to make words easier to eat. When you have promised to eat your words, it's easier if you've minced them first.

I don't believe it. In fact, I don't believe any of this. Is any of it true?

Professor Wordsmith writes: No, not a bit of it. But it's a lot more interesting than the true explanations.

Professor Wordsmith will be back again soon. Keep these trivial queries rolling in.