- Assessee
- Asset
- Assignor
- Assimilated
- Assistance
- Assize
- Associate
- Associated
- Astrodome
- Astrolobe
- Astrologer
- Astute
- Astuteness
- Aswathi star
- Aswini devas
- At a gun point
- At one time
- At ones risk
- At ones sweet soil
- At peak
- At play
- At sea
- At sixes and sevens
- At stake
- At the eleventh hour
- At the longest
- At the same time
- At the top of ones voice
- Atone
- Atonement
- Atrocious
- Atrocities
- Atrorcious
- Attaching
- Attachment
- Attachments
- Attacker
- Attain
- Attempt the impossible
- Auctioneer
- Audibility
- Audibleness
- Audibly
- Audit
- Audition
- Auditor
- Aught
- Augmented reality
- August-september
- Augustly
- Authorized person
- Autistic
- Auto index
- Auto-ignition
- Autobiography
- Autodidact
- Automation
- Autonomy
- Avionics
- Awake
- Awe
- Awe-inspiring
- Awestruck
- Awhile
- Awkwardly
- Awn
- Altaltissimo
- Ark
- Astron
- Ataxia, ataxia
- Act up to
- Acting
- Actinic
- Actinotherapy
- Action plan
- Actions
- Actions speak louder than words
- Activation
- Active and passive voices
- Activex
- Add to
- Addenda
- Additionally
- Address size
- Adenoids
- Adept
- Adequacy
- Administratively
- Administrator
- Admirably
- Admiralty
- Admire for
- Admired
- Admissible
- Admittedly
- Admix
- Admonish
- Adolescence
- Adopted
- Adorable