- apical
- aplanat
- apodyterium
- apophyge
- apothem
- apparatus
- apparatus dewpoint
- apparent
- apparent heave
- apparent inertial
- apparent porosity
- apparent size
- apparent stress
- apparent throw
- apparition
- appeal
- appease
- append
- appendage
- apple
- appliance
- application
- application equipment
- applied geology
- applied load
- applied moment
- apply name
- appreciation
- apprehension
- approach cutting
- approach embankment
- approach road
- approach span
- appropriate excitation
- appropriate procedure
- approval
- approve
- approximate
- approximate analysis
- appurtenances
- apron
- apron elevator
- apron flashing
- apron lining
- apron wall
- apse
- aquatic
- arabesque
- arbitrary excitation
- arbitrate
- arbitration
- arbitration test
- arbor
- arboretum
- arc
- arcaded cornice
- arch abutment
- arch beam
- arch brick
- arch core
- arch dam
- arch scaffolding
- arch stress
- arch tie
- arched
- arched spillway
- architect association
- architectonic morphology
- architectural clearance
- architectural concept
- architectural design
- architectural drafting
- architectural engineering
- architectural form
- architectural heritage
- architectural lighting
- architectural module
- architectural ornament
- architectural planning
- architectural semiotics
- architectural structure
- architectural symbol
- architrave cornice
- archives
- area
- areaway
- arenaceous
- argil
- argillaceous sandstone
- arid climate
- applied informatics
- appraise
- apprentice
- approximate formula
- apron piece
- aquatic system
- aqueduct
- aqueous corrosion
- aqueous dispersion
- aquifer