- 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
- Agoraphobic
- Avoirdupois
- Amaranthus
- Antiquary
- Auctor
- A bad pill to swallow
- A bed of roses
- A bird in hand is worth two in the bush
- A bit much
- A blood relative
- A cardinal error
- A dead duck
- A dead luck
- A dear john letter
- A disciple who lodges with his preceptor
- A divine ministrel
- A dogs life
- A dry
- A false alarm
- A fiche
- A fish
- A floating voter
- A form of verse in which each line contains eight letters
- A golden parachute
- A good innings
- A good thing
- A grain of paddy
- A hollow laugh
- A host in himself
- A jam session
- A kings ransom
- A lack all
- A laughing stock
- A lazy susan
- A little water
- A man of few words
- A man of mark
- A matter of fact
- A matter of life and death