The word "grub-ax" refers to a tool used for digging out roots and grubbing up soil. It can also be called a mattock, pick mattock, or digging hoe. The mattock has a blade on one end and a pick on the other, making it useful for chopping away tough soil and cutting through roots. A pick mattock is similar but has a pointed end that's better suited for breaking apart rocks and heavy ground. The digging hoe, on the other hand, has a curved blade that helps to scoop and move soil around. No matter the name, these tools are essential for digging up and moving soil, making them valuable for gardening, landscaping, farming, and construction.