'mind-numbing' originates from the combination of 'mind' and 'numb,' where 'mind' refers to the mental faculties and 'numb' means lacking sensation or feeling.

'mind-numbing' evolved from the concept of 'numbing the mind' to describe something so dull it affects mental alertness.

Initially, it meant 'causing the mind to become numb,' but over time it evolved into its current meaning of 'extremely boring or dull.'