Real tennis is seldom seen* but if you do happen to find a court then the tambour is a sloping buttress on the hazard end of the court:
(Look, the vocabulary of real tennis is a delight in itself.)
Easier to spot is the tambour which is a pair of hoops, one inside another, that hold a piece of fabric stretched tightly like a drum-skin so you can embroider on it without the whole thing going all puckered or wavy.
The sort of embroidery or lace done on such a frame is called tambour, too.
But tambour doesn't stop there. You have a desk with shutters at the top which part sideways like curtains? Also known as a tambour desk. You can see a circular dome? It's probably supported by a wall called a tambour.
That's the Dome of the Rock in Jerusalem.
You can hear a drum? Well, I'm sorry about that, but a tambour is a drum, too. One like this:
Tambour d'Arcole, Sculpture by Jean Barnabé Amy
If in difficulty with this Spot the Frippet, a cake storage tin or hat box can easily be pressed into service as a tambour.
But please note that this blog takes no responsibility for any attack or injury thus evoked.
Spot the Frippet: tambour.This word is French, from tabour, tabor, from the Persian tabīr.
*By real tennis I don't mean the stuff that was played before the days of the Big Serve, but the game played by, for instance, king of England Henry VIII. Real here, as in Real Madrid, means royal.