ETYMOLOGY
from Latin nefastus (contrary to, or forbidden by divine law),
from ne- (not) + fastus (lawful for the transaction of business) (from fas – wicked act, moral offense)
EXAMPLE (for adj. 1.)
“… The day of the moneth wherein he was borne, should be adiudged and accounted for an vnluckie, dismall, and nefast day, wherevpon it shoulde not be lawfull for any iudge to sit. …”
From: Beautifull Blossomes
By John Bishop, 1577
Lexicophilia 