When a group of people line up and an individual comes along and does something sexual or has sex with each one, one by one!

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 police technique in which a handful of people fitting a similar description are stood in a line together for a witness of a crime to see. The witness is then supposed to pick out the perp.

A queue of prostitutes, often of varying ethnicity and hair color, arranged linearly against a flat surface, normally a facade, for the purpose of offering patrons a very wide selection. The lineup is most commonly seen in the area that is common to various gentlemen's clubs, and the prostitutes are normally just getting off their gentlemen club shifts to make some extra money.

The biggest problem with the lineup is the patrons have to find somewhere nearby (outside) after making their selection. The lineup is most commonly found in cities like Atlanta, Miami, and Las Vegas.

a) The performers that are going to be at a music festival.

b) When surfing, the waves break at a certain point. All the surfers are behind that point in a line, as to not get in the way when one is paddling for a wave that is about to break. That is the "lineup".

the area beyond the breaking waves where surfers wait for a ride.

(Canadian, noun) Line or queue.