Black"-let`ter, a. 1.
Written or printed in black letter; as, a black-letter
manuscript or book.
2. Given to the study of books in black letter;
that is, of old books; out of date.
Kemble, a black-letter man!
J. Boaden.
3. Of or pertaining to the days in the calendar not
marked with red letters as saints' days. Hence: Unlucky;
inauspicious.