- working surface
- workstation
- Wheatstone network
- wheeling
- white
- wide angle
- Wiegand effect
- Wilson experiment
- winch
- wind speed
- winder
- winding
- window infiltration
- wiregrating
- wiring harness
- wobbe transmitter
- wolfram
- wellit
- wet evaporation
- wet filter
- wet outlet
- Wetherill separator
- wettability properties
- wetted deck
- wetting
- whistling meteor
- Wiedemann effect
- Wiegand wire
- Wilson electroscope
- wind turbine
- winding overhang
- windmill
- winter conditions
- wiring
- withdrawn refrigerant
- withstand test
- wood spirit
- work function
- working cycle
- working range
- working voltage
- wort cooler
- wound rotor
- Wronskian
- X-amplifier
- X-plates
- X-radiation
- x-ray
- x-refrigerant
- x-unit
- xerography
- Y circulator
- y network
- Y-amplifier
- Y-voltage
- yard
- yield
- YIG device
- Yjunction
- yoke
- yoke permeameter
- yoke suspension
- young star
- Youngstown switch
- Z pinch
- z-transform
- z-transformation
- zone thermostat
- Zeeman effect
- Zener breakdown
- Zener voltage
- zenith telescope
- zero
- zero beat
- zero car
- zero component
- zero method
- zero potential
- zero sound
- zero temperature
- zigzag connection
- zigzag leakage
- zigzag reflections
- zinc white
- zircon
- zodiac
- zodiacal
- zodiacal constellation
- zodiacal light
- zone control
- zone refining
- zoning
- zoom