- approved
- appurtenance
- arc cutter
- arch acting
- arch girder
- arch-type
- area adjustment
- argillaceous
- arm
- arm saw
- armature
- arrange
- arresting stop
- arterite rock
- artesian
- artesian discharge
- artificial cooling
- artificial drainage
- arm crane
- armor clamp
- armored car
- armoured
- artesian area
- artesian pressure
- articulate
- articulated arm
- articulated suspension
- artificial abutment
- as cast
- asbestos packing
- asbestos sheet
- asbestos tape
- ascentional motion
- ash stop
- asphalt distributor
- asphaltic
- assembly
- assign
- asbestine
- ascension
- ash cell
- ashy
- asphalt grout
- asphalt injection
- assembly opening
- assistant engine
- assumed elevation
- astatic
- astrogeodetic point
- astronomical azimuth
- at par
- atmometer
- atmospheric front
- atomization
- atomizer
- arable
- arbitrary
- arbitration analysis
- archwise
- arcing
- areometer
- argentan
- aridity
- arm center
- arm mixer
- arm stirrer
- armalac
- armor
- armor-plate
- armored cables
- armored truck
- armour
- arroyo
- arterial
- arterial drainage
- artery
- artesian flow
- articuiar lamella
- artificial recharge
- ashore
- assembly floor
- associated rock
- atmidometer
- atmospheric humidity
- attaching clamp
- attemperator
- attendance
- attendant
- attention signal
- attenuate
- attenuation
- attrition mill
- atubos steel
- auger
- automated assembly
- automated machining
- automated welding
- automatic clutch
- augmenter
- aurrent lathe