sicko in English dictionary sicko Meanings and definitions of "sicko" (Australian, slang) A day taken off work due to (a possibly exaggerated or supposed) illness. (derogatory, slang) A person with unpleasant tastes, views or habits. (US, Canada, slang) A mentally ill person. noun (Australia, slang) A day taken off work due to (possibly exaggerated or supposed) illness. noun (derogatory, slang) A person with unpleasant tastes, views or habits. noun (US, Canada, slang) A mentally ill person. more Grammar and declension of sicko sicko ( plural sickos or sickoes) sicko (plural sickos or sickoes) more Sicko Sample sentences with "sicko" Declension Stem Try again Available translations Arabic Catalan Chinese Czech Danish Dutch Estonian Finnish French German Greek Hungarian Italian Japanese Macedonian Norwegian Persian Polish Portuguese Romanian Slovak Spanish Swedish Ukrainian Authors