1580s, skowndrell, "base, mean, worthless fellow," a word of unknown origin. Century Dictionary, citing Skeat, makes it perhaps ultimately from the source of shun. Another suggestion is Anglo-French escoundre (Old French escondre) "to hide, hide oneself," from Vulgar Latin *excondere, from Latin condere "to hide, put away, store," from assimilated form of com- "together" (see com-) + -dere "put" (from PIE root *dhe- "to put, place"). The main objection is the hundreds of years between the two words. OED thinks the sense has strengthened since 18c., to "audacious rascal, one destitute of all moral scruple." Related: Scoundrelly.