Morning sickness is a misnomer -- it can strike any time.
-- Jane Bartlett, "Sick, and tired of it", Guardian, June 20, 2000
Copy cat is a misnomer because cats never copy anybody.
-- Carl Van Vechten, The Tiger in the House
The distinction between monkeys and apes is still muddled in the popular mind: Chimpanzees, gorillas, and orangutans are still frequently called "monkeys," and very good monkeys, such as Barbary "apes" and Celebes black "apes," continue to carry their misnomers.
-- Noel T. Boaz Ph.D., Eco Homo
Misnomer is from Medieval French mesnommer, "to misname," from mes-, "wrongly" + nommer, "to name," from Latin nominare, "to name," from nomen, "a name."