Look at these:
These little birds are white wagtails. There are lots of varieties, but they're all much the same. The English one is called the pied wagtail.
The reason it's called the pied wagtail is firstly because it's pied (ie black and white) and also because it wags its tail a lot, probably to frighten insects into moving so they can seen and snapped up.
That's one of the marvellous things about words: they tell us what people see when they look at things.
If you're from the English county of Sussex, for instance, you might see this little bird quite differently. There the pied wagtail is sometimes called a Dishwiper or a Dishlick (it spends a lot of its time beside water). In Hampshire and Somerset it might be called a Molly Washdish.
Spanish wagtails do washing, too: they're lavandera blanca: but in Italy, they are, most beautifully, the ballerina bianca, and the tail-wagging has become a graceful dance.
German wagtails are, oddly, rather idle. They just stand in streams on stilts (or perhaps the correct translation is knuckles, because they have quite short legs): Bachstelze.
In Shetland, however, the wagtail is associated, not with the countryside but with the church: it's a kirk sparrow, I suppose this is because it wears black and white like a clergyman (kirk is church).
In Holland, as in England, it's the flicking tails that are noticed: they're the witte kwikstaart.
They're white in Russia, too (they're the white shake-rump, Белая трясогузка) but in France they're grey: little grey sheperdesses (or possibly little grey hillfolk): bergeronnette grise. That's when they're not hochequeue, nod tails.
One small bird, and so many ways of seeing it.
What do you see where you are?
Word To Use Today: wagtail. This word...hey, but there's really no need, today, is there.