Lewd remarks are sexually inappropriate. Personal and sexually explicit comments might be acceptable when said in private, but they are not all right when said to strangers in public.
Lewd has to do with sexual behavior or remarks that are highly inappropriate or obscene, often because of what's done or said is in public or to someone who does not want that kind of attention. The couple who might make sexually suggestive jokes in private with each other would be completely out of place doing the same thing in the supermarket. What's more, committing a lewd act or making inappropriate comments is socially — and legally — unacceptable, and it can even land the perpetrator in jail.