What is the X in X-mas?
"morbid fear of cats," 1905, from -phobia "fear" + ailouros "cat," of unknown origin. Folk etymology connects it with aiolos "quick-moving" + oura "tail." Related: Ailurophobe (1914).
ailurophobia ai·lu·ro·pho·bi·a (ī-lur'ə-fō'bē-ə, ā-lur'-)n. An abnormal fear of or aversion to cats.