Personal Defense Weapon. Originally used to describe HK's MP5K (MP for Maschine Pistole or Machine Pistol and K for "Kurtz" meaning small). The term has since left being used to describe that weapon and has grown to represent a new class of weaponry that is supposed to have the firepower of a rifle (such as a M16 series rifle in 5.56mm)yet the ease of carry of a submachine gun (like the larger MP5 variants).

Two weapons currently fit such a description, FN Herstal's FNP90 (5.7x28mm)and HK's MP7 (4.6x30mm). Both of these weapons are marketed as being perfect for support staff and pilots where a full size rifle would be too large to be practical
The Belgian army has units that are issued PDW 's
by Seriphimarchangel November 20, 2008
Personal Defense Weapon.

The PDW is a submachine gun, manufactured by Heckler & Koch, that is compact, lightweight, low recoil, and fast firing. Strangely, this does not seem to be a very good weapon for personal defense because it is still an SMG: larger than a handgun, and is a wee bit overpowered for neutralizing your common criminal.

The standard PDW and the newer MP7-PDW could very well outclass the MP5 in the police force \ SMG field, except for its smaller magazine capacity.
You could probably put 20 PDW shots into someone before they hit the floor. A bit of overkill when a single shot from a weak pistol would disable them.
by Kenthar November 7, 2003
Piss Drinking Whore, one who drinks their own or other people urine for enjoyment or a wannabe pornstar who drinks piss for the chance to audition.
Suzy is a PDW! She let some guy piss in her mouth just so he'd make her a portfolio!
by bayla October 9, 2006
person 1: Those guys are all dick weeds, but that one guy is a pdw.

person 2: whats a pdw?

person 1: professer dick weed
by Sarah and dominic March 29, 2009
Public Display of Weirdness. Similar to a PDA - but for the coolest kind of idiot.
Bro 1: -does strange dance-
Bro 2: Dude, PDW's aren't acceptable in front of your girl!
by :):):):):):););) November 19, 2011
Peter David Weber. A professional bowler known for his flamboyant TV antics and D-Generation-X crotch chops after bowling strikes. Most notable for his nonsense saying "Who do you think you are? I AM!!!" directed to his detractors after winning his 5th US Open.
by LGM87 April 7, 2013
Possession of a dangerous (or deadly) weapon in violation of applicable laws.
After finding a gun on the seat of the car in plain sight, the officer slapped handcuffs on the suspect while telling him, "You're under arrest for felony PDW."
by Anthony Brancato April 20, 2003