What does "on duty" mean?

Actively engaged in an assigned task, duty or occupation.

What is a synonym for "on duty"?

Common synonyms include: at it, at work, busy, call, employed, engaged.

prep_phrase

prep_phrase ·Rare ·Advanced level

Prep_phrase

1
Actively engaged in an assigned task, duty or occupation.
"I'm supposed to go on duty at 0800 hours."

"I'm supposed to go on duty at 0800 hours."