Etymology
From Middle English sliken, from Old English *slīcan (“to crawl, slink”), from Proto-West Germanic *slīkan, from Proto-Germanic *slīkaną (“to creep, crawl”), from Proto-Indo-European *sleyg-, *sleyǵ- (“to glide, smooth, spread”). Cognate with German Low German slieken (“to slink, crawl”), German schleichen (“to creep, crawl, slink, sneak”), Old English slīcian (“to make sleek, slick, smooth, or glossy”).