- A posteriori
- A power in the land
- A pyramid scheme
- A queen mother
- A race against time
- A resaissance man
- A roof over ones head
- A safe best
- A safe job
- A shade
- A siva chant
- A skeleton in the cupboard
- Above the weather
- Above-ground
- Aboveboard
- Abrasion
- Abridge
- Abridgment
- Abrigement
- Abrus
- Abscond with
- Absent-minded
- Abstraction
- Absurd drama
- Abusive words
- abuzz
- Acacia
- Academician
- Academics
- Accompaniments
- Accomplish
- Accomplished
- Accomplishment quotient
- Accordant
- Accorded
- Accordingly
- Accountrements
- Accounts payable
- Accounts receivable
- Accoustics
- Acetic acid
- Ache
- Acid lemon
- Acidophilus
- Acidulous
- Acknowledge
- Acknowledged
- Acm
- Acne
- Acorn
- Acoustic
- Act of peace
- Action meter
- Action-packed
- Activate
- Active server pages
- Active service
- Active voice
- Actively
- Activeness
- Activewear
- Actress
- Actual
- Actualise
- Adhere
- Adhering
- Adjacent
- Adjoin
- Adjudge
- Adjudication
- Adjudicator
- Adjunct
- Adman
- Administer
- Administrating
- Administration
- Administrative
- Administrative system
- Adorer
- Adorning
- Adroitly
- Adulteress
- Adumbrate
- Adumbration
- Affulment
- Aerial combat
- Aerial root
- Aeriform
- Aerobatic
- Aerodynamics
- Aerogramme
- Aeronaut
- Aeronautics
- Aeroplane
- Aesthetic
- Aesthetics
- Afar
- Affable
- Affecting
- Aflame