Word To Use Today: bum-clock.

Sometimes words make the mind boggle: what on earth, one must  wonder upon first encountering it, can a bum-clock be?

Some sort of an aid to achieving regular calls of Nature?

But no, it's not that.

What do you think it is?

No, sorry, not even close. 

A bum-clock is a beetle.

In Scotland it's a beetle that makes a droning noise as it flies: 


this is a cockchafer or may bug. Photo by Gail Hampshire

but in England bum-clock has been used to mean any insect that hums.

It all makes a bit more sense when you know that bum is another word for hum (and, pleasingly, that something that bums a lot is bumbling...which is, of course, what bumblebees do).


photo by Martin Falbisoner

As for the clock bit...

...sorry, no one's got a clue about that, but the word clock has been used to mean beetle since 1550. A clock-leddy, for instance, is a ladybird.