Webster's Revised Unabridged Dictionary · 1913

Black Monday

Black Monday ({not transcribed})

1.
Easter Monday, so called from the severity of that day in 1360, which was so unusual that many of Edward III.'s soldiers, then before Paris, died from the cold. — Stow
Then it was not for nothing that my nose fell a bleeding on Black Monday last. — Shakespeare
2.
The first Monday after the holidays; -- so called by English schoolboys. — Halliwell