1) Certain work unit 2) Ergonomics unit 3) Industrial production unit 4) Unit of work 
A man-hour is the amount of work performed by the average worker in one hour. It is used in written `estimates` for estimation of the total amount of uninterrupted labour required to perform a task. For example, researching and writing a college paper might require twenty man-hours. Preparing a family banquet from scratch might require ten man-h.....
[n] - a time unit used in industry for measuring work
person hour noun a time unit used in industry for measuring work