Lime

Это, конечно, все знают:

There was a young man from Peru
Whose limericks stopped at line two.

СЯУ ("Сегодня Я Узнала", аббревиатура заимствована у avva), что у этого лимерика есть вот такой извод:

There was an old maid from Verdun

The joke being that "Verdun" rhymes with one, so it can be inferred that if there was a second line, it would say "Whose limericks all stopped on line one."
(and even with an explanation that the narrator knows an unrecitable limerick about Emperor Nero)