ludus, -i, m.
In the usage I’ve seen and in my dictionary, ludus can mean both school and play. In LL, the kids in school are always in ludo, but from my dictionary, it seems I could also use the same phrase for kids “at play.” Are these both commonly expressed with ludus?
Many thanks in advance,
Chris
Judging by the way my Korean kids behave in class, I don’t think there’s much of a difference. 
David
I believe the primary and original meaning of ‘ludus’ is “organized sport” – a “game” in the sense of a spectacle put on for other people (like in modern English: “a football game”)
From there, it seems the meaning expanded to include any activity where a group of young people got together and trained and exercised themselves, so it’s not too hard to imagine how this word could be expanded to include the meanings “school”, “play” and also “joke/fun”
HA! The Romans were probably well aware of this fact as well. 
This makes perfect sense. Thank you!
Chris