- agrobiology
- agrochemistry
- agronomic pedology
- air chipper
- air conveyor
- air engine
- air heater
- air impermeability
- air injector
- air level
- air manifold
- air nozzle
- air outlet
- air passage
- air pump
- air receiver
- air soring
- air test
- air traffic
- air turbine
- air vacuum
- aircraft
- agricultural atlas
- agricultural engineer
- agroclimatology
- aid
- aiming point
- air box
- air chamber
- air clutch
- air cylinder
- air drilling
- air inlet
- air line
- air reservoir
- air seasoning
- air space
- air tool
- air-dry
- air-hardened
- aircraft carrier
- aisle
- aircraft steel
- aircushion craft
- airfoil
- airship
- airside face
- airworthiness
- alarm
- albaloy