I am looking for an example of a pair of adjectives or nouns (broadly defined) in classical Latin which mean the same thing but one is considered rude and the other one polite. I could list several such pairs of politically incorrect and correct phrases in English or Finnish, but no Latin ones come to mind and I wonder whether the phenomenon existed then as it does today. For English examples, consider "blind" vs. "visually impaired" or "nigger" vs. "African-American". There are many kinds of political (in)correctness and it is also a matter of opinion. I hope, however, that the concept is clear enough.
Can anyone give a similar pair in classical Latin? How do we know that there is such a difference in tone? If there are several such pairs, a well-attested or otherwise prominent example would be great.