Cum sancto

Cum sancto sanctus eris, cum perverso perverteris is a wise proverb.   It means roughly - with the holy man you will be holy, with the wicked man you will be wicked.  Thanks to Laura Gibbs, on whose Bestiaria Latina Blog I found this proverb.  Laura attributes it to Polydorus, however a quick search on Google shows that it comes from 2 Samuel, chapter 22, verses 26 and 27, which in the Latin Vulgate reads:

26. cum sancto sanctus eris et cum robusto perfectus  
27. cum electo electus eris et cum perverso perverteris 

Sopor Aeternus & Saltatio Mortis

Sopor Aeternus, which means eternal sleep, is the apt name of a German dark wave musical project.  Saltatio Mortis, which means dance of death, is a German medieval metal band.

sopor, soporis (m)  sleep; apathy
aeternus adj.  eternal; immortal
saltatio, -onis (f)  dance
mors, mortis (f)  death; corpse.

English words from mors, mortis and from aeternus are not hard to find.  The adjective soporific comes, of course, from sopor, soporis.

Fenestra

Fenestra, -ae (f) meaning window is another Latin word which has passed in to various languages.

Dutch  venster
French  la fenetre (f) [the circumflex on the middle e has been omitted]
German  das Fenster (n)
Italian  finestra (f)
Welsh  ffenestr (f)

The English noun window is, of course, unrelated, however we do have a very specific verb from fenestra - defenestrate, which means to throw a person out of a window.