Inefficient

[Tina]

Not efficient; not producing the effect intended or
desired; inefficacious; as, inefficient means or measures.

[Sommer]

Not achieving maximum productivity; wasting or failing to make the best use of time or resources.

[Jessica]

The word used to describe a [lazy ass] [coworker] who sits around on his [cell phone] all day who to tries to call his boss inefficient.