smug

Where it comes from

Originally "spruce, neat," from Low German smuk (“pretty”), from Middle Low German smuk (“lithe, delicate, neat, trim”), although the g of the English word is not easily explained. The ultimate source should be Proto-West Germanic *smeugan (“to crawl, creep”).

From the Low German derived also North Frisian smok, Danish smuk and Swedish smukk (now obsolete or dialectal).

Compare also Middle High German gesmuc (“ornament”) and smücken (“to dress, to adorn”), both ultimately from smiegen (“to press to, insert, wrap, to nestle”), hence German schmiegen, Schmuck and schmücken. The adjective schmuck, however, was borrowed from Low German. See smock for more.