from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of or relating to the four-day period between the old and new moon when the moon is not visible.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of the four-day period between an old moon and a new moon, when it is not visible
from the GNU version of the Collaborative International Dictionary of English
- adj. Belonging or pertaining to the time when the moon, at or near its conjunction with the sun, is invisible.
from The Century Dictionary and Cyclopedia
- Pertaining to the moon's monthly interval of invisibility; between the periods of moonlight: as, interlunar nights. The interlunar cave is the place of seclusion into which the moon was anciently supposed to retire at such times.
inter- + lunar: compare Latin interlunis. (Wiktionary)