Blood Moon Meaning

(idiomatic, astronomy) The moon as it appears during a total lunar eclipse.

Example: 2006, Georgiana Kotarski, Ghosts of the Southern Tennessee Valley, ISBN 9780895873262, pp. 98-99 (Google preview):
  Just after two o'clock in the morning, the moon went into eclipse, fading to a deep red and casting a pall over the mountainside. Viewing the blood moon as an ominous sign, the Confederates used it to cloak their flight.
2014, Gaynor Hall, "Blood Moon Rising: Chicago star gazers in for treat if weather holds out," (retrieved 15 April 2014):
  â€œBecause the Earth has an atmosphere, it doesn’t completely block the light on the moon. Some of the red light actually bends through the Earth’s atmosphere and lights up the moon during a total eclipse, and that’s the rusty red, blood moon,” said SubbaRao.