Throw ups are a type of tag, which in turn is a form of ad-hoc, quick graffiti.

Throw ups are often only one or two colors, and are a very unembellished symbol, letter, abbreviation, or short word.

Taggers (people who tag) often throw up a tag like this everywhere they go.

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.

The act of vomiting. The term 'throw up' is usually considered less offensive than words such as 'puke' or 'barf.'

A throw up is a quick graffiti bomb. Usually not the writer's full name. An Unfilled throwie is a hollow. If a throwie is filled its usually a crack-fill(quick back and forth strokes with fill colour).

The term throw up comes from the fact that the bomb is just thrown up on a wall, bus, train, etc very quickly.

A simple outline with a 1 layer paint fill-in. usually done in the initials of your name.

a quick freestyle graffiti bomb

a graffiti marking composed of a fill and outline done quickly with spray paint on a vertical surface