Rude is what you call someone with no manners: pushing past you, talking over you, taking the last chair without asking. A rude waiter, a rude reply to a polite email, the rude silence when you say good morning and get nothing back.
Rude covers two different offences. One is bad manners; the other is dirty — a rude joke, a rude word, a rude drawing on the back of an exercise book. That second sense is very British and slightly childlike. The grammar is fixed: you are rude TO someone, and it is rude TO DO something, as in it's rude to point. A rude awakening has nothing to do with manners at all: it is a sudden unpleasant discovery, like opening the heating bill in January. In older writing rude means rough and roughly made — a rude hut, rude tools. The noun is rudeness.
1adjectiverudeHaving no manners; showing no respect for other people.
“It was rude of him to leave without thanking anyone.”
synonyms: discourteous, ill-mannered
2adjectivecrudeReferring to sex or the body in a way that shocks or makes people laugh.
“The children were giggling over a rude word in the dictionary.”
3adjectivesuddenSudden and unpleasant, used before nouns like awakening and shock.
“The first electricity bill was a rude shock.”
4adjectiveroughlyRoughly made from whatever was to hand.
“They built a rude shelter out of branches and a tarpaulin.”
Too few real examples of this word to estimate which sense is commonest.
Also accepted in games: impolite
Rude came through Old French from Latin rudis, which described land that had never been ploughed and material that had never been worked: rough, raw, wild. English kept that meaning for centuries, so a rude shelter was a badly built one, not an impolite one. The modern sense is the same word turned on a person — unfinished, unpolished, never smoothed down by manners.
Latin
rudis — rough, raw, rude, wild, untilled
Old French
rude
Middle English
rude
English, today
rude
From Middle English rude, from Old French rude, ruide, from Latin rudis (“rough, raw, rude, wild, untilled”).
Etymology from Wiktionary, CC BY-SA