A string trimmer, also called a “weed-whacker” or a “weed eater”, is a tool which uses a flexible monofilament line instead of a blade for cutting grass and other plants near objects, or on steep or irregular terrain. It consists of a cutting head at the end of a long shaft with a handle or handles and sometimes a shoulder strap.

String trimmers may also be known as whipper snippers, weed whips, edge trimmers, line trimmers, and strimmers.