The term 'TOOL FOR A ZEN GARDEN' can be summarized as a RAKE, which is a four-letter word. A RAKE is a gardening tool used to create patterns in the sand or gravel of a Zen garden. It is usually made of wood or metal and has a long handle with a row of metal or plastic teeth at the end. Rakes are used to create intricate designs in the sand or gravel, which can be used for meditation or contemplation.