- alluvial formation
- alluvial placer
- alluvial river
- alluvial valley
- alluvium period
- alluvium precipitability
- almoclastic rock
- alongshore
- aloxite closure
- alternate
- alternate irrigation
- alternating deposit
- alternating gradient
- alternating strain
- alternation
- alternative
- alternative project
- altimeter
- altimetric data
- altitude
- altitude effect
- altitude range
- aluminium rivet
- aluminium solder
- ambit
- amorphous rock
- amortization
- amphibious
- amphoric
- ample
- amygdaloid
- analysis certificate
- analyzer
- anchor bolt
- anchor mixer
- anchorage
- ancillary
- angle shears
- angle-cutter
- angled
- anglepoise lamp
- angular data
- angular grain
- angular slip
- angular strain
- angularity
- annealing point
- annual intensity
- annual output
- anomalousness
- anormal
- antarctic front
- antecedent river
- anti-knock
- anti-rust
- angle cock
- angle lever
- angle pitch
- angle scale
- angle tolerance
- angling adjustment
- angular clearance
- angular correction
- angular dam
- angular milling
- angular pitch
- angular seam
- angular stop
- angular-shaped
- anisometric
- anisotropic fabric
- annealed casting
- annealed steel
- annealing
- annual amplitude
- annual inspection
- annual reservoir
- annual variation
- annular gap
- annular jet
- anode cleaner
- anorganogene rock
- anormal rock
- amorphism
- amorphous
- analytics
- anchor
- anchorage fascine
- antecedent precipitation
- anticarburizing compound
- anticasehardening compound
- anticorrosive admixture
- anticorrosive solution
- anticreep collar
- anticreep control
- anticrustator
- anticyclonic
- antidetonamit
- antidetonant
- antidribble