- analog recorder
- analog systems
- anaphoresis
- anastigmatic lens
- antenna coil
- antenna crosstalk
- antenna detector
- antenna field
- antenna gain
- antenna polarization
- antenna resistance
- anteroom
- antiapex
- antibaryon
- anticipatory control
- anticoincidence
- anticommute
- anticondensate heater
- anticondensation
- anticondensation device
- antideflagrating equipment
- antidust agent
- antielectron
- antiferroelectric
- antiferroelectricity
- antiferromagnet
- antiferromagnetic
- antiferromagnetic ferroelectric
- antiferromagnetic material
- antiferromagnetic resonance
- antiferromagnetic substance
- antiferromagnetic susceptibility
- antiferronmagnon
- antifreeze heater
- antifreeze thermostat
- antifreezing lubricant
- antifreezing oil
- anderson bridge
- Andrews" curves
- Andronikashvill experiment
- anechoic
- anechoic chamber
- aneroid barometer
- anfractuous conduit
- angle noise
- angular aperture
- angular correlation
- anisentropic
- anisochronous
- anisotropic conductivity
- annealing temperature
- annular
- annular conductor
- annular flow
- annunciator
- anode drop
- anodoluminescence
- antenna efficiency
- antenna loading
- antenna pair
- antiglare
- antigravity
- antihalo
- antihyperon
- antikaon
- antimagnetic
- antimeson
- antimony electrode
- antineutrino
- antinucleon
- antiparticle
- antiproton
- antiproton annihilation
- antiquark
- antireflection
- antireflection lens
- antiresonance
- antiresonant circuit
- antirot substance
- antisoliton
- antispectroscpic
- antistatic
- antistatic agent
- antisymmetry
- aperiodic waves
- aperiodicity
- aperture antenna
- aperture circle
- aperture correction
- aperture illumination
- aperture stop
- aperture synthesis
- apex
- aplanat
- aplanatic
- aplanatic lens
- aplatism
- apochromat
- apochromatic lens
- apochromatism