black-letter

black-letter is an   Adverb

Definition:

[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[2] Given to the study of books in black letter; that is, of old books; out of date.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.

Synonyms: