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Given to the study of books in black letter; that is, of old books; out of date.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.
© Webster 1913.