Once again, here is the original Latin of the Cambridge Latin Course.
poeta tabernam intrat. poeta in taberna stat et versum recitat. versus est scurrilis. Caecilius ridet. sed tonsor non ridet. tonsor est iratus.
The Cambridge Latin Course translates scurrilis as ‘rude’ but the full story is far more interesting. (By the way, when pronouncing scurrilis, put the stress on the ri – scurrilis.)
The mighty Oxford Latin Dictionary declines to translate, instead saying that something scurrilis (such as a joke or abuse) is ‘characteristic of a scurra’. And what is a scurra? Again, according to the OLD, a scurra is ‘a fashionable city idler, a man about town’. How quaint; that doesn’t seem so bad, does it? But the quality of a scurra, what makes a scurra a scurra, is their scurrilitas (again, stress the ‘ri’). And that quality? Untimely or offensive humour. There is an adverb too, which allows something to be done scurriliter, or with untimely jests. We’ve all been there. And there is even a cute little diminutive, scurrula, which the OLD defines as ‘a joker' or 'a wag’.
But I have left the best till last. Horace gives us the verb scurror, scurrari, scurratus sum (Ep I.17.19), which basically means ‘to use your reputation for telling untimely and offensive jokes to get yourself invited regularly to dinner parties’. Awesome.
The sailor enters the barber shop. The sailor stands in the barber shop and recites a verse. Claudia laughs. But Alan does not laugh. The verse is the kind of rude joke that one might tell to get themselves invited to a dinner party.