Risible

Laughable, ridiculous

This word once meant “capable of laughter”, like “Man is a risible animal”, but it’s meaning has transferred from active to passive, the same error as using “done” to mean “finished”.

Examples:

The reciprocal civility of authors is one of the most risible scenes in the farce of life.
— Samuel Johnson, The Life of Browne (1756)

The adventure of the fulling-mills in Don Quixote, is extremely risible, so is the scene where Sancho, in a dark night, tumbling into a pit, and attaching himself to the side by hand and foot, hangs there in terrible dismay till the morning, when he discovers himself to be within a foot of the bottom.
— Lord Henry Home Kames, Elements of Criticism (1761)

Orwell’s attempt to connect the leader of the Petrograd Soviet to the stalwarts of “Dad’s Army” is nearly, but not quite, risible.
— Christopher Hitchens, Why Orwell Matters (2002)

Etymology:

Risus is latin the past tense of ridere, to laugh, so this can be remembered as coming from the same word as “ridicule”, however different it now sounds.