Bonsai is two words, "Bon", and "Sai". The word "Bon" means "tray"
and "Sai", "growing" or "planting". Therefore, the two words put together give the translation of "tray growing" or "tray planting".  Over time this has become known as the art of miniaturising trees, and is, therefore, a technique which can be practised on any woody stemmed plant material.  Miniaturising takes place as a result of confining to a shallow pot and top pruning.