- Asking
- Aslant
- Asleep
- Aspects
- Aspersion
- Assafoetida
- Assail
- Assam
- Assassinate
- Assault
- Assay
- Assured
- Asthenia
- Astis
- Astonished
- Astraddle
- Astral body
- Astray
- 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
- Aunt
- Aureate
- Aurora
- Auster
- Austere
- Auteur
- Authenticate
- Authentication
- Authorised
- Authoritarianism
- Authoritative
- Authorized person
- Autistic
- Auto index
- Auto-ignition
- Autobiography
- Autodidact
- Automation
- Autonomy
- Avionics
- Awake
- Awe
- Awe-inspiring
- Awestruck
- Awhile
- Awkwardly
- Awn
- Adp
- Airily
- 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 man of few words
- A man of mark
- A matter of fact
- A matter of life and death
- A measure of
- A milk-n-honey drink
- A narrow escape
- A nasty one
- A near death experience
- A needle in a haystack