“My Lords, it would I think be conducive to clarity of analysis of the ingredients of a crime that is created by statute, as are the great majority of criminal offences today, if we were to avoid bad Latin and instead to think and speak … about the conduct of the accused and his state of mind at the time of that conduct, instead of speaking of the actus reus and mens rea.” ~ Lord Diplock in R v Miller, [1983] 1 All ER 978 (House of Lords, England)
So what is actus reus? Lord Diplock explains, earlier in this same judgment:
“This expression is derived from … ‘Actus non facit reum, nisi mens sit rea,’ by converting incorrectly into an adjective the word reus which was there used correctly in the accusative case as a noun.”

