- Assembling
- Assertion
- Assessment
- Assets
- Assignation
- Assignee
- Assimilation
- Assist in
- Associates
- Association
- Astrogeology
- Astroid
- Astrologers
- Astronaut
- Astrophysicist
- Asvamedha sacrifice
- Asymmetrical
- Asymptote
- At a loose end
- At a price
- At a run
- At one leisure
- At one's fingertips
- At ones last gasp
- At ones own pace
- At that
- Atomic theory
- Atomic warfare
- Atomic weight
- Atoms
- Atomy
- Atony
- Atriculate
- Attach
- Attack
- Attacked
- Attained puberty
- Aubade
- Auberage
- Aubergine
- Aubum hair
- Auction
- Auctionary
- Audience
- Audio
- Audio-visual aids
- Auditory ossicles
- Augean stables
- Augmentation
- Augur
- Augury
- Authoritatively
- Authority
- Authorization
- Authorized
- Autism
- Auto-typography
- Autochthons
- Autocrat
- Autograph
- Automatic dictionary
- Automatic pagination
- Automatism
- Await
- Awaiting
- Awake to
- Awake to reality
- Awareness
- Awash
- Awful
- Awkward age
- Awl
- Ax
- Axe helve
- Axiom
- As such
- Atomism
- Alienist
- Almirah
- Amen!
- Antiquarianism
- Arm
- Atdm
- A drop in the ocean
- A fair treat
- A feather in one's cap
- A fellow believer
- A few
- A fight to the finish
- A fighting chance
- A figure of squaresused in holy spells
- A fly on the wall
- A gem
- A good deal
- A good or great many
- A hen party
- A herb with the smell of camphor
- A historical
- A hollow laughter
- A la