- A amplifier
- a prior
- a priori
- a truss
- a-point
- A-UX
- abbreviate
- abbreviated address
- abbreviated dialing
- abbreviation
- Abelian category
- Abelian variety
- ability test
- abnormal
- abnormal function
- abnormal reflection
- abnormality
- abort
- aborted connection
- aborting procedure
- about
- abraded glass
- absolute
- absolute base
- absolute conic
- absolute continuity
- absolute coordinate
- absolute derivative
- absolute deviation
- absolute extensor
- absolute function
- absolute integrability
- absolute language
- absolute maximum
- absolute path
- absolute pathname
- absolute positioning
- absolute programming
- absolute rest
- absolute summability
- absolute value
- absolute velocity
- absolutely
- absolutely compact
- absorbing barrier
- absorbing screen
- absorbing state
- absorption frequency
- absorption probability
- abstract