A chainsaw was a mechanical device used on Earth for cutting. Other planets also utilized such a device, even for rituals.
In 2152, Hoshi Sato questioned whether Enterprise NX-01 had a chainsaw onboard. Captain Jonathan Archer later used one to chop up the trunk of an alvera tree as part of a Kreetassan apologetic ritual. (ENT: "A Night in Sickbay")
In 2381, Doctor T'Ana used a chainsaw to amputate a crewman's foot that had been latched onto by an alien lifeform. (LD: "Mining The Mind's Mines")