As always, if you would like to make an addition or correction, PM the moderator!

4R70W.....4spd, RWD, 700 ft-lbs, wide ratio [transmission]
AED.........Allen Engine Development (maker of supercharger kit for Panthers)
A/F..........Air/Fuel [ratio]
ADBV......Anti-Drain Back Valve (on OEM-style oil filter)
AMMX......Aluminum Metal Matrix (driveshaft substrate)
AODE......Automatic OverDrive (Electronic) [transmission]
BMSC......Blower Motor Speed Controller
CAFE.......Corporate Average Fuel Economy
CEL.........Check Engine Light (MIL is correct term)
CKP.........Crankshaft Position Sensor
CMP........Camshaft Position Sensor
COP........Coil-On-Plug (ignition system)
CR...........Compression Ratio
CTS.........Coolant Temperature Sensor (see ECT)
DOHC......Dual OverHead Camshaft (two cams per cylinder bank)
DPFE.......Differential Pressure Feedback EGR sensor (measures EGR flow)
EATC.......Electronic Automatic Temperature Control
ECT.........Engine Coolant Temperature (sensor)
EEC.........Electronic Engine Control (integral part of PCM)
EGR.........Exhaust Gas Recirculation valve
EPC..........Electronic Pressure Control (solenoid in transmission)
EVO.........Electronically Variable Orifice (power steering)
FI...........Forced Induction
HEGO......Heated Exhaust Gas Oxygen sensor
HVLA.......Hydraulic Valve Lash Adjuster
IAC.........Idle Air Control valve
IAT..........Intake Air Temperature [sensor]
KS...........Knock Sensor
LCM.........Lighting Control Module
LSD.........Limited Slip Differential
MCC.........Modulated Converter Clutch
MIL..........Malfunction Indicator Light
MLPS........Manual Lever Position Sensor (gearshift sensor, on tranny)
MY..........Model Year
NA...........Naturally Aspirated
OBD........On-Board Diagnostics
O2S........Oxygen Sensor (see HEGO)
PATS.......Passive Anti-Theft System
PCM........Powertrain Control Module
PI...........Performance Improved (cylinder heads found on 2001+ Panthers)
RAR.........Rear Axle Ratio
REP.........Romeo Engine Plant
SOHC......Single OverHead Camshaft (one cam per cylinder bank)
SRS.........Supplemental Restraint System (airbags)
SS1/SS2...Shift Solenoids (in transmission)
STAP.........St. Thomas Assembly Plant (Ontario)
TB...........Throttle Body
TC...........Torque Converter (also Traction Control, TownCar)
TCC.........Torque Converter Clutch (lockup clutch)
TPS.........Throttle Position Sensor
WAP........Wixom Assembly Plant
WCM.......Wiper Control Module
WOT.......Wide Open Throttle
VSS.........Vehicle Speed Sensor (on trans tailshaft)
YIS..........Years In Service

We've neglected this list for a while so here are a bunch of new ones. Some serve the same function as before but have been renamed, and some are not used on panthers but are good to know.

4R75W: 4 speed, RWD, 750 ft-lbs, Wide-Ratio (04 CVPI and MM)
4R70E: 4 speed, RWD, 700 ft-lbs, Electronic Control w/ Wide-Ratio gearset (some 05 panthers)
4R75E: 4 speed, RWD, 750 ft-lbs, Electronic Control w/ Wide-Ratio gearset (Most 06+ panthers)
2V: Two-Valve (per cylinder - SOHC)
3V: Three-Valve (per cylinder - SOHC)
4V: Four-Valve (per cylinder - DOHC)

ABS: Anti-lock braking system
ACT: Air Charge Temperature sensor (see IAT)
APP: Acceleration Pedal Position sensor
AT: Automatic Transmission / Ambient(Outside) air Temperature sensor (EATC)
ATC: Automatic Temperature Control (EATC predecessor)
ATF: Automatic Transmission Fluid
BDA: Blend Door Actuator
BJB: Battery Junction Box (battery fuse panel)
BP: Barometric Pressure sensor
BPP: Brake Pedal Position switch
BPS: Brake Pedal Switch (see BPP)
BOO: Brake On/Off switch (see BPP)
CAI: Cold Air Induction
CAN: Controller Area Network (used on 05+ panther multiplex network)
CCM: Comprehensive Component Monitor
CHT: Cylinder Head Temperature sensor (98+ used for FSC)
CJB: Central Junction Box (interior fuse panel)
CNG: Compressed Natural Gas
CV: Crown Victoria
CVPI: Crown Victoria Police Interceptor
CYL: Cylinder
DBW: Drive by Wire (false but common term for ETC)
DDM: Driver's Door Module (95+ - Controls RKE and auto-down driver's window)
DRL: Daytime Running Lamps
DSM: Driver's Seat Module (used on panthers w/ memory seats)
DTC: Diagnostic Trouble Code
DTR: Digital Transmission Range sensor (same as MLPS) - also Dark Toreador Red (color)
EDIS: Electronic Distributor-less Ignition
EEPROM: Flash Electrically Erasable Programmable Read Only Memory
EFI: Electronic Fuel Injection
EFT: Engine Fuel Temperature sensor
EOT: Engine Oil Temperature sensor
ESM: EGR System Module
EST: Electronic Stability Control
ETA: Electronic Traction Assist
ETC: Electronic Throttle Control
ETCA: Electronic Throttle Control Actuator
EVAP: Evaporative Emission
EVP: EGR Valve Position sensor
EVR: EGR Vacuum Regulator Solenoid
FEAD: Front End Accessory Drive (serpentine)
FFS: Flexible Fuel Sensor
FFV: Flexible Fuel Vehicle
FLI: Fuel Level Input
FMEM: Failure Mode Effects Management
FPM: Fuel Pump Monitor
FPDM: Fuel Pump Driver Module
FPR: Fuel Pressure Regulator (-02)
FPRCS: Fuel Pressure Regulator Control Solenoid
FRP: Fuel Rail Pressure sensor
FRT: Fuel Rail Temperature sensor
FRPT: Fuel Rail Pressure & Temperature sensor (03+ panther)
FSC: Fail-Safe Cooling (98+)
FTP: Fuel Tank Pressure sensor
GEM: Generic Electronic Module (see LCM for panthers)
GENLI: Generator Load Input
GM/GMQ: Grand Marquis
GVW: Gross Vehicle Weight
GVWR: Gross Vehicle Weight (curb weight + payload)
HID: High Intensity Discharge (headlamps)
HLOS: Hardware Limited Operation Strategy
HO2S: Heated Oxygen Sensor (same as HEGO)
IAB: Idle Air Bypass (see IAC or IAB for supercharger application)
IAT: Intake Air Temperature Sensor and Idle Air Trim
IAT2: Intake Air Temperature Sensor #2 (post forced induction)
I/C: Intercooler/Inter-cooled
ICT: In-Car Temperature sensor
IEIS: Integrated Electronic Ignition System
IFS: Inertia Fuel Shutoff switch
ILEV: Inherently Low Emission Vehicle.
IMRC: Intake Manifold Runner Control (-'98 DOHC modular)
IMRCM: Intake Manifold Runner Control Monitor
IMSC: Intake Manifold Swirl Control
IMTV: Intake Manfild Tuning Valve
KAM: Keep Alive Memory
LEV: Low Emission Vehicle
LTC: Lincoln Town Car
MAP: Manifold Absolute Pressure
MCN: Multiplex/Module Communications Network (95+)
MGM: Mercury Grand Marquis (see GMQ)
MM: Mercury Marauder
MPI: Multi-Port Injection
NGV: Natural Gas Vehicle (see CNG)
OCT ADJ: Octane Adjust shorting bar
OD: Overdrive (4th gear in AOD and AODE family)
OSCM: Occupant Seat Classification Module
OSCS: Occupant Seat Classification Sensor (01+ panther)
OSS: Output Shaft Speed sensor (01+ panther)
PCV: Positive Crankcase Ventilation (valve and/or system)
PDB: Power Distribution Box (same as BJB)
PFE: Pressure Feedback EGR (older version of DPFE - single hose)
PFS: Purge Flow Sensor (EVAP)
PTO: Power Take-Off
PSP: Power Steering Pressure switch/sensor
PSWM: Passenger Seat Weight Module (see OSCM)
PSWS: Passenger Seat Weight Sensor (see OSCS)
PWM: Pulse Width Modulation (illumination)
RAS: Rear Air-Suspension
RCM: Restraints Control Module (01+ panther)
RLC: Reverse Lamp Control
S&B: Shake and Bake! :P
SCDS: Speed Control Deactivation switch
SCB: Supercharger bypass (see IAB)
SCB: Supercharger Boost solenoid (Lightning)
SCP: Standard Corporate Protocol (used on 95-04 Panther's multiplex network)
SCT: Superchips Custom Tuning
SEFI: Sequential Electronic Fuel Injection
SI: Sequential Injection (see SEFI)
SIR: Supplemental Inflatable Restraint
SLC: Stop Lamp Switch (see BOO)
SSA/SSB: Shift Solenoid A/B (new name for SS1/2)
TAC: Throttle Actuator Control (05+ panther)
TCS: Transmission Control Switch (od lockout)
TCIL: Transmission Control Indicator Lamp (o/d off lamp)
TFT: Transmission Fluid Temperature sensor
THC: Thermostat Heater Control
TMAP: Thermal Manifold Absolute Pressure (see MAP)
TRAC: Traction Control (98+) or Traction Assist (-'97)
TSS: Turbine Shaft Speed sensor (05+ (trans))
ULEV: Ultra Low Emission Vehicle.
VAC: Vacuum
VCT: Variable Cam Timing
VECI: Vehicle Emission Control Information
VLCM: Variable Load Control Module
VMV: Vapor Management Valve (EVAP)
VVT: Variable Valve Timing
WAC: Wide Open Throttle A/C Cut-Off
ZEV: Zero Emission Vehicle