 The word derives from Old English "smearcian", via Middle English "smirken".It is from the same root as "smile", from Proto-Germanic "*smar-", but with a velar root extension "-k-" (with intensive or frequentative function) particular to English also found in "talk" (from the root of "tell") and "stalk" (from the root of "steal") etc.The specific meaning of a mocking or unpleasant, malicious smile or grin develops in Early Modern English, but until the 18th century, it could still be used in the generic sense " to smile".