The term 'perversely humorous' can be described as 'ironical, ' which is an 8-letter word. Irony is a figure of speech in which words are used to convey the opposite of their literal meaning. It is often used to express humor, sarcasm, or ridicule. Irony can be used to make a point or to emphasize a situation. Perversely humorous irony is when someone uses irony to make a joke that is inappropriate or offensive.