Regarding context, historical, or otherwise--
Words that are very bad today were commonplace and innocuous in medieval times.
Okay, RISK warping your computer screen FOREVER, but I post links to Geoffrey Chaucer's
Canterbury Tales (Indeed, my thread here is okay to read in polite society, more or less, but the links 'could' fry your computer):
http://english.fsu.edu/canterbury/miller.html
Check out line 3276, amongst others. This was a commonplace word beginning with the letter T, and completely harmless then (late 1300's), but it is not something one would use in American society (well, maybe I lack a filter sometimes...

). In Britain, this word is still used more freely. I have seen folks in the presence of several other folks that they don't know well, thwack a horse on the side and tell it to quit being a t___! (In the UK, it is pronounced differently than here, rhymes with hat, in the US, it rhymes with what).
See line 324 in the attachment:
http://www.librarius.com/canttran/reevt ... 14-344.htm
Again, a word today, although increasingly commonplace, is still considered a very bad word. Over 600 years ago, it wasn't considered that bad.
There is another very bad word that is even worse than the 'F bomb' that one certainly would not use today in the presence of the ladies, and it was used in place of the word (e.g., synonymous to) alluded to in line 3276 of the first attachment. Indeed, it was the word that I recall when I had to read the
Canterbury Tales when I was in school. Indeed, when I saw that word (with glee), English class quickly went from dodgy and boring to exciting indeed!
If anyone has seen the HBO series
Deadwood the F bomb is used throughout. Indeed, I researched this topic as I was curious if this word was used as freely as in the show. Well, not the case, but producers, if they used particularly racy terms from the 1800's, realized it would be lost upon a modern audience. For example, dad-blame it was regarded as particularly bad in the day, and means nothing today. If you are curious, check out the following:
http://www.authentic-campaigner.com/for ... -1097.html
One last thing about context and a time and place: I recall being at a British railroad station in the mid-1990's, and an American couple calls out to their child that if they don't behave, they will smack the child on the fanny, in front of several individuals, mostly Brits. (My apologies if I have offended any UK readers on this forum). In the US, it is okay to say that to anyone, including a child...in the UK, it is a very bad word.
Again, it is ALL about the times and the context.