Mar 07, 2014 11:18 PM

Origin late Middle English: from Jack, nickname for the given name John . The term was used originally to denote an ordinary man (sense 6), also a youth (mid 16th cent.), hence the “knave” in cards and “male animal.” The word also denoted various devices saving human labor, as though one had a helper (sense 1, sense 3, sense 9, and sense 10, and in compounds such as jackhammer and jackknife); the general sense “laborer” arose in the early 18th cent.