Normally, I wouldn't bring this up, but...
The Webster's 1913 entry below is a good example of social censorship. The obvious meaning of tit, a term for a breast, is wholly absent. However, tit is actually one of the oldest words in the English language. It comes from the Old English word titt, not titter, and means "tit" or "teat." (Teat has the same origin.)
It also is a cross-cultural word (like Ambrose claimed "bella donna" was). It is influenced by the Old French tette. This isn't the amazing coincidence that this might be -- tette is borrowed from Old German, a sister language to Old English.
The most important words are universal in a culture group. "Mama" and "No" (the first words a child learns) mean the same thing in umpteen Indo-European languages. As an aside, Papa is a close third, while "Yes" varies a bit by language (Yes ("Yeah"), Ja, Da, Si, Oui, etc.). Why? Because dads are sometimes, but not always, in the picture, while all parents say "No" more often that "Yes" to the little ones.
Where am I going with this? With a tongue-in-cheeck observation that tit is the first word that men care about.
(Now if only someone would do a similar write-up for ass...)