Definitions for "ESU"
Electro-Static Unit
NYPD mergency ervices nit, a combination of a Rescue Squad and SWAT Team. ESU has been referred to as the "Oh Shit! Boys." When a cop arrives at a call, takes one look around and says, "Ohhhh shit!" there's probably a need for ESU to respond. There is another saying about ESU. "When the public needs a cop, they call NYPD. When a cop needs a cop, he calls ESU." ESU is perhaps the finest unit of its kind in the world, and regularly cross-trains with the Secret Service, FBI, Customs, INS, IRS, Red Cell and other high-profile SWAT/Tactical teams.
Evolutionary Significant Unit. A population that 1) is substantially reproductively isolated from conspecific populations and 2) represents an important component of the evolutionary legacy of the species.