A wall used jointly by two parties under easement agreement, erected upon a line dividing two parcels of land, each of which is a separate real estate entity; a common wall.

1. Blue Monday is the most depressing day of the year, calculated by Dr. Cliff Arnall, a researcher at the University of Cardiff's Center for Lifelong Learning.
Factors used to calculate the date included weather conditions, debt level, time since Christmas, time since failing our New Year's resolutions, low motivation and feeling the need to take action.

In 2005 the date was calculated as January 24th, in 2006 it was January 23rd, and in 2007 it was January 22nd.

2. A song by the hard rock band Orgy from their album Candy Ass.

A phrase used by pretentious architects, often incorrectly, to refer to a sound cancelling wall between two adjacent condominium units.