- primary voltage
- priming time
- prismatic colour
- probability amplitude
- probable
- probe particle
- proceed
- process control
- process modeling
- process path
- process refrigeration
- processed
- processed ice
- processing cooler
- product temperature
- product refrigeration
- product tray
- profile chart
- programmable ROM
- programming
- progressions
- prohibited
- projection microscope
- projection television
- projector
- prom
- prominence
- proofed tape
- propagation
- propagation coefficient
- propagation delay
- propagation length
- propagation mode
- propagation velocity
- propane compressor
- propane-operated
- propeller turbine
- proper variable
- proportionality
- propylene glycol
- protective thermostat
- programmable controller
- programming device
- programming unit
- progress
- projectile particle
- projecting lantern
- projection chamber
- projection welding
- prolate ellipsoid
- PROM-eraser
- proportionality law
- propellant
- propelling agent
- proper absorption
- proper field
- proportional band
- proportional control
- propulsion
- prospective current
- protective grounding
- protective switch
- protector
- protector gap
- protector tube
- proton microscope
- proton synchrotron
- PSC motor
- pseudo particle
- pseudo-acid
- pseudo-base
- pseudo-period
- pseudo-potential
- pseudo-stationary
- pseudo-tensor
- psychrometric condition
- psychrometric diagram
- psychrometric formular
- psychrometric measurement
- psychrometric process
- psychrometric properties
- psychrometric tables
- psychrometry
- PTC thermistor
- PU system
- protective conductor
- protector block
- protium
- proton accelerator
- proton magnetometer
- proton stability
- protostar
- prototype
- protuberance
- proximity switch
- pseudo-crystal
- pseudo-equilibrium
- pseudo-morphy
- pseudo-paradox
- pulldown operation