The Definition of Naughty [Rhyme] Schemes
Ooh, an even better BoingBoing link– “The Omnificent English Dictionary in Limerick Form is a project to write a definitional limerick for every single word in the Oxford English Dictionary.”
Artery
The arteries carry the blood;
Without them our bodies would flood.
They’re elasticized — sorta;
The chief’s the aorta.
If it ruptures, that’s all for you, Bud!
Naturally, I couldn’t resist looking up whether meta-themed entries existed yet. No limerick definition (limerition?) yet for “dictionary”, but “limerick” has been covered:
Limerick
The limerick’s not anapestic,
However it is quite elastic;
The subject it covers
Is frequently lovers’
Activities, normal and drastic.
Anyone got any (not too dirty) favorites to share?

