rude |roōd|

adjective
1 offensively impolite or ill-mannered : she had been rude to her boss | [with infinitive ] it’s rude to ask a lady her age.
• referring to a taboo subject such as sex in a way considered improper and offensive : he made a rude gesture.
• [ attrib. ] having a startling abruptness : the war came as a very rude awakening.
2 roughly made or done; lacking subtlety or sophistication : a rude coffin.
• archaic ignorant and uneducated : the new religion was first promulgated by rude men.
3 [ attrib. ] chiefly Brit. vigorous or hearty : Isabel had always been in rude health.

DERIVATIVES
rudely adverb
rudeness noun
rudery |-ərē| noun

ORIGIN Middle English (in sense 2, also [uncultured] ): from Old French, from Latin rudis ‘unwrought’ (referring to handicraft), figuratively [uncultivated] ; related to rudus ‘broken stone.’

THE RIGHT WORD
Someone who lacks consideration for the feelings of others and who is deliberately insolent is rude (: It was rude of you not to introduce me to your friends).
Ill-mannered suggests that the person is ignorant of the rules of social behavior rather than deliberately rude (: an ill-mannered child), while uncivil implies disregard for even the most basic rules of social behavior among civilized people (: his uncivil response resulted in his being kicked out of the classroom).
Rough is used to describe people who lack polish and refinement (: he was a rough but honest man), while crude is a more negative term for people and behavior lacking culture, civility, and tact (: he made a crude gesture).
Uncouth describes what seems strange, awkward, or unmannerly rather than rude (: his uncouth behavior at the wedding).
Although people of any age may be rude, crude, ill-mannered, or uncouth, callow almost always applies to those who are young or immature; it suggests naiveté and lack of sophistication (: he was surprisingly callow for a man of almost 40).