monotasking

The performance by an individual of one task, and only one task, at a point in time. Monotasking can be more productive than multitasking because it allows an individual to put all their attention and focus on the task at hand. This allows fewer mistakes than would be made if the individual were multitasking.

"With so much time on his hands, Peter decided to monotask for the rest of the day."

"Bob told me that monotasking is so much better than multitasking."