by Misadventures of Crow "Doggerel is poetry that is irregular in rhythm and in rhyme, often deliberately for burlesque or comic effect. The word is derived from the Middle English dogerel, probably a derivitive of dog. In English it has been used as an adjective since the 14th century and a noun since at least 1630.
Appearing since ancient times in the literatures of many cultures, it is characteristic of nursery rhymes and children's song." (via Wikipedia)
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Bad verse traditionally characterized by clichés, clumsiness, and irregular meter. It is often unintentionally humorous. The “giftedly bad” William McGonagall was an accomplished doggerelist, as demonstrated in “The Tay Bridge Disaster”:
It must have been an awful sight,
To witness in the dusky moonlight,
While the Storm Fiend did laugh, and angry did bray,
Along the Railway Bridge of the Silv’ry Tay,
Oh! ill-fated Bridge of the Silv’ry Tay,
I must now conclude my lay
By telling the world fearlessly without the least dismay,
That your central girders would not have given way,
At least many sensible men do say,
Had they been supported on each side with buttresses,
At least many sensible men confesses,
For the stronger we our houses do build,
The less chance we have of being killed.
- http://www.poetryfoundation.org/learning/glossary-terms?category=forms-and-types