Answer: workaholic

AnswerCrossword Clue
WORKAHOLIC

He sleeps with his briefcase

WORKAHOLIC

Nonstop doer

WORKAHOLIC

Person who doesn't know when to quit

WORKAHOLIC
Sleep-deprived employee, maybe
WORKAHOLIC
Employee who rarely takes off
WORKAHOLICNine-to-niner
WORKAHOLICNine-to-niner, e.g.
WORKAHOLIC9-to-9er