- At length
- At will
- Atelophobia
- Atheism
- Atheistic
- Athri
- Athwart
- Atlantic
- Atmosphere
- Atom
- Atomic
- Atomic number
- Attendant
- Attending
- Attentive
- Attestation
- Attractiveness
- Atwitter
- Au courant
- Aunt
- Aureate
- Aurora
- Auster
- Austere
- Auteur
- Authenticate
- Authentication
- Authorised
- Authoritarianism
- Authoritative
- Autopsy
- Autotype
- Autumn
- Avacado
- Avarise
- Aver
- Average
- Avid
- Avidly
- Aviform
- Axle-tree
- Azolla
- Azure
- 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 plant with sweet-scented roots
- A plum job
- A pretty kettle of fish
- A pretty penny
- A quixotic project
- A variety of sida
- A safe pair of hands
- A sea of
- A shot in the arm
- A shot in the locker
- A signal achievement
- A sorry sight
- Abaddon
- Abandoned
- Abandoned woman
- Abandonment
- Abased
- Abashed
- Abba
- Abbreviation
- Abbreviator
- Aberrant
- Abnormally
- Abode assylum
- Abolishment
- Abolitionism
- Abolitionist
- Abominable snowman
- Abomination
- Aboriginal
- Abreaction
- Abortive
- Abounding in waves
- About-face
- About-turn
- Above
- Above ones head
- Above ones reach
- Absently
- Absolute
- Aqiqah
- Absorb in
- Absorbed
- Absorbent
- Absorbing
- Abstract art