Rude respiration is an archaic term with no modern usage. However, if we were to consider antonyms for the word "rude," we may look at words like polite, mannerly, courteous, or respectful. These words connote a sense of decorum and etiquette that would be the opposite of being rude. Similarly, when looking for antonyms for "respiration," we may consider words like choking, asphyxia, or suffocation, as these are conditions that would prevent normal breathing. Conversely, we could also look at words like breathing, inhalation, or oxygenation, which would describe normal respiration. Overall, it is important to consider the context in which antonyms are being used as it determines which word would provide the best opposition.