working.

A physical therapist is on duty in the fitness center from 7 a.m. until 9 p.m.

He didn't have time to talk about it right then because he was on duty for another three hours.

Usage notes: usually said about soldiers, police, medical workers, and people who work a scheduled period of time

• ebb and flow
• ebb and flow of
• ebb and flow of something
• effing and blinding
• either feast or famine
• either way
• elbow grease
• elbow room
• elders and betters
• elevator music
• eleventh-hour
• empty nest syndrome
• Empty vessels make most noise.
• Empty vessels make most sound.
• Empty vessels make the most noise.
• Empty vessels make the most sound.
• end it all
• end justifies the means.
• end of story
• End of story.
• end of the line
• end of the road
• endowed with
• endowed with something
• end up