What it means
A greenhorn is a newbie who's still finding their feet and making all the classic first-timer mistakes. It's the fresh face on site, on the crew, or in the game who doesn't know the shortcuts yet and can still get caught by obvious jokes or basic stuff. Usually it's teasing, not savage. Everyone starts out green.
Usage examples
"Go easy on the greenhorn, it's only his first week on the job."
"As a greenhorn I fell for every wind-up the older crew threw at me."
"You can tell he's a proper greenhorn, still checking which end of the drill does the damage."
"Don't rinse her too hard, she's a greenhorn and only started bartending last night."
Where it comes from
Recorded in English since the 1600s, greenhorn has long meant an inexperienced newcomer. Green carries the old sense of unripe or not ready yet, and horn likely taps into the image of young animals with new horns. Put together, it paints someone still raw, still new to the whole circus.
