Doggerel

Doggerel is a derogatory word, dating from late 13th/early 14th century that means trivial or undignified verse, deriving from the figurative use of the word dog meaning a contemptuous, worthless, cowardly fellow. (The same meaning is evident in phrases like dog Latin.) Rym dogerel (rhyme doggerel) is mentioned by Chaucer in Canterbury Tales (c. 1387). Doggerel verse is first attested from 1630 according to the OED.