blue moon

noun
High School
1

The third full moon in a season that contains four rather than the usual three full moons.

2

The second of two full moons that occur in the same calendar month (a definition created by mistake in the 20th century).

3

The moon tinted towards blue as it appears in the sky, caused by dust or smoke in the atmosphere.

4

A long time.

5

A bright blue, sweet-flavored ice cream that is popular in the Midwestern U.S. and is a component of Superman ice cream.

#rare