Crudely made; primitive.
Violent; abrupt; turbulent.
Somewhat obscene, pornographic, offensive.
Lacking in refinement or civility; bad-mannered; discourteous.
Undeveloped, unskilled, inelegant.
Hearty, vigorous; found particularly in the phrase rude health.
Lacking refinement or skill; untaught; ignorant; raw.
Insufficiently cooked, so as to be unpalatable or inedible.
Very lightly cooked.
The broccoli was nicely undercooked.
Done with insufficient energy, enthusiasm, etc.