A labour-saving thing makes a particular job easier, so you need less time or less physical effort. A washing machine is a classic labour-saving device; so is a dishwasher, or a tool that cuts a kitchen or factory job down. You will meet it most often in front of device, gadget, or equipment, and in adverts. It does not mean the person is lazy, and it does not mean someone is “saving labour” like saving money in a bank. Though actually, a tool sold as labour-saving sometimes only moves the work (you clean the machine instead). American English writes labor-saving; this form with labour is British.