- Water clusters
- Water conflict
- Water conservation
- Water consumption
- Water content
- Water cooler
- Water cooling
- Water cycle
- Water cycle management
- Water damage
- Water demand management
- Water dimer
- Water dispenser
- Water distribution system
- Water droplet erosion
- Water efficiency
- Water export
- Water extraction
- Water filters
- Water filtration
- Water fluoridation
- Water footprint
- Water gas
- Water gas shift reaction
- Water hammer
- Water heating
- Water industry
- Water injection
- Water jacket
- Water landing
- Water level
- Water main
- Water management
- Water mass
- Water metering
- Water meters
- Water model
- Water of crystallization
- Water pinch
- Water pinch analysis
- Water pollution
- Water potential
- Water privatization
- Water pumping
- Water purification
- Water quality
- Water quality modelling
- Water reducer
- Water resources
- Water retention curve
- Water scarcity
- Water scarcity in India
- Water security
- Water softening
- Water splitting
- Water stagnation
- Water stress
- Water supply
- Water supply network
- Water table
- Water tanks
- Water testing
- Water towers
- Water treatment
- Water turbines
- Water vapor
- Water wheels
- Water year
- Water-cement ratio
- Water-energy nexus
- Water-gas shift reaction
- Water-tube boilers
- Water-use efficiency
- Waterborne resins
- Waterfall model
- Waterfall plot
- Waterfalls
- Waterless fracturing
- Waterline
- Watermark
- Waterproof
- Waterproofing
- Watershed delineation
- Watershed management
- Watersheds
- Watertight door
- Waterways
- Watson
- Watson and Crick
- Watt
- Wattle
- Wattle and daub
- Wattmeter
- Wave
- Wave base
- Wave drag
- Wave equation
- Wave field synthesis
- Wave function
- Wave height
- Wave impedance
- Wave interference
- Wave loading
- Wave overtopping
- Wave packets
- Wave power
- Wave radar
- Wave run-up
- Wave shoaling
- Wave soldering
- Wave surface
- Wave tank
- Wave turbulence
- Wave vector
- Wave-particle duality
- Wavefront
- Waveguide filter
- Waveguides
- Wavelab
- Wavelength
- Wavelength shifter
- Wavelet
- Wavelet transform
- Wavelet-OFDM
- Wavellite
- Wavemeter
- Wavenumber
- Waveplate
- Waviness
- Wax
- Wax emulsion
- Wax esters
- Wayfinding
- Waypoint
- Wc
- Weak acids
- Weak artificial intelligence
- Weak base
- Weak convergence
- Weak derivatives
- Weak duality
- Weak encryption
- Weak formulation
- Weak key
- Weak localization
- Weak ordering
- Weak reference
- Weak selection
- Weak supervision
- Weak topology