A form of comic verse invented by Edmund Clerihew Bentley (1875-1956). It lacks meter but has a fixed rhyme scheme of aabb - two rhyming couplets. The clerihew succinctly sums up a subject or character:

The art of Biography
Is different from Geography.
Geography is about maps,
But Biography is about chaps.

But the clerihew at its most infamous is a witty and largely uninformative miniature biography:

Geoffrey Chaucer
Could hardly have been coarser,
But this never harmed the sales
Of his Canterbury Tales.