'single-tasker' originates from the combination of 'single' and 'task,' where 'single' meant 'one' and 'task' meant 'a piece of work to be done.'

'single-tasker' evolved from the concept of 'single-tasking,' which became popular in the late 20th century as a counter to 'multi-tasking.'

Initially, it referred to a person who could only handle one task at a time, but now it often implies a preference for focusing on one task for better efficiency.