Lewd means crudely and offensively sexual. Lewd remarks, lewd behaviour, lewd gestures.
It is a formal and legal word — lewd conduct and lewd behaviour appear in charge sheets — and outside that it sounds slightly archaic. It is stronger than rude and more disapproving than crude. Note that the word originally meant lay rather than clerical, then unlearned, then coarse: the slide from not a priest to not decent took about four hundred years and says something about who could read.
1adjectivelewdCrudely and offensively sexual.
“He was thrown out of the bar for making lewd comments to the waitress.”
lewd is a quality of obscenity.
Old English laewede meant lay, as against clergy. It slid through unlearned to coarse to indecent, which is a long fall for a word that once meant only not a priest.
Old English
lǣwede — unlearned, ignorant, lay
Middle English
lewed
English, today
lewd
Built from
From Middle English lewed, lewd, leued (“unlearned, lay, lascivious”), from Old English lǣwede (“unlearned, ignorant, lay”), of unknown origin. Formally similar to a derivative of the past participle of Old English lǣwan (“to reveal, betray”) in the sense of "exposed as being unlearned" or "easily betrayed, clueless", from Proto-West Germanic lāwijan, from Proto-Germanic lēwijaną (“to betray”), from lēwą (“an opportunity, cause”), from Proto-Indo-European lēw- (“to leave”). If so, then cognate with Old High German gilāen, firlāen (“to betray”), Gothic 𐌲𐌰𐌻𐌴𐍅𐌾𐌰𐌽 (“to give over, betray”), Gothic 𐌻𐌴𐍅 (“an opportunity, cause”). Or, according to the OED, probably from Vulgar Latin laigo-, from Latin lāicus (“of the people”), from Ancient Greek λαϊκός.
Etymology from Wiktionary, CC BY-SA
Practised in A Song of Ice and Fire