. . . is that anyone can contribute to it. Mistakes or deliberately misleading statements are therefore only removed if someone with better knowledge notices them. This is probably the case with the Lavinia = Purity entry, which states no sources or background information.
A quick check of an online Latin-English dictionary revealed no trace of Lavinia as a word, and gave "incontaminatus, putus, incorruptus, purus, caste, caste" as words relating to pure and purity. Another Latin resource gave the following words starting with lav- :
lavabrum -i n. [a bath]. lavatio -onis f. [washing , bathing; bathing apparatus]. Lavinia -ae f. [daughter of Latinus , wife of Aeneas]. lavo lavare or lavere lavi lautum or lotum or lavatum [to wash , bathe; to moisten, wet; to wash away]. Hence partic. lautus -a -um, [washed]; hence [fine, elegant, sumptuous, refined]; adv. laute.
I'd say it's safe to assume that BtN is correct on this one.
♦ Chrisell ♦
All we have to decide is what to do with the time that is given us. - J.R.R. Tolkien.