Found 2 items, similar to blue moon.
English → English (WordNet)
Definition: blue moon
blue moon
n : a long time;
“something that happens once in blue moon
almost never happens”
English → English (gcide)
Definition: blue moon
Moon
\Moon\ (m[=oo]n), n. [OE. mone, AS. m[=o]na; akin to D.
maan, OS. & OHG. m[=a]no, G. mond, Icel. m[=a]ni, Dan. maane,
Sw. m[*a]ne, Goth. m[=e]na, Lith. men[*u], L. mensis month,
Gr. mh`nh moon, mh`n month, Skr. m[=a]s moon, month; prob.
from a root meaning to measure (cf. Skr. m[=a] to measure),
from its serving to measure the time. [root]271. Cf.
Mete
to measure,
Menses,
Monday,
Month.]
1. The celestial orb which revolves round the earth; the
satellite of the earth; a secondary planet, whose light,
borrowed from the sun, is reflected to the earth, and
serves to dispel the darkness of night. The diameter of
the moon is 2,160 miles, its mean distance from the earth
is 240,000 miles, and its mass is one eightieth that of
the earth. See
Lunar month, under
Month.
[1913 Webster]
The crescent moon, the diadem of night. --Cowper.
[1913 Webster]
2. A secondary planet, or satellite, revolving about any
member of the solar system; as, the moons of Jupiter or
Saturn.
[1913 Webster]
3. The time occupied by the moon in making one revolution in
her orbit; a month. --Shak.
[1913 Webster]
4. (Fort.) A crescentlike outwork. See
Half-moon.
[1913 Webster]
5. The deliberately exposed naked buttocks. [slang]
[PJC]
Moon blindness.
(a) (Far.) A kind of ophthalmia liable to recur at
intervals of three or four weeks.
(b) (Med.) Hemeralopia.
Moon dial, a dial used to indicate time by moonlight.
Moon face, a round face like a full moon.
Moon madness, lunacy. [Poetic]
Moon month, a lunar month.
Moon trefoil (Bot.), a shrubby species of medic (
Medicago arborea
). See
Medic.
Moon year, a lunar year, consisting of lunar months, being
sometimes twelve and sometimes thirteen.
blue moon, see
blue moon in the vocabulary.
[1913 Webster]
blue moon
\blue moon"\
The second full moon occurring in the same month; -- derived
from the expression
once in a blue moon; as, we had a blue
moon on January 31, 1999, and another in March.
[PJC]
once in a blue moon very rarely; -- from the observation
that the moon rarely has a bluish tint.
Note: In 1980, the phrase
blue moon was applied to the
second full moon of any month, because this phenomenon
is unusual. This new meaning for the old phrase blue
moon has become widely accepted.
[PJC]