- Are
- Area code
- Arena
- Areola
- Argania
- Argon
- Armoury
- Armpit hair
- Arms race
- Army
- Arouses
- Arrack
- Arras
- Array
- Arraying
- Arrear
- Arrive
- Arrogance
- Articles of association
- Articulated
- Artillary
- Artilleryman
- Artiodactyl
- Artocarpus heterophyllus
- Artocarpus hirstula
- Arundhati star
- As a result of
- As per rule
- As poor as a church mouse
- As silent as a grave
- As well as
- As-much-as-one-can-do
- Asbestos
- Ascc
- Askance
- Asmall box of chunna
- Asoka forest
- Asokatree
- Aspen
- Aspergillum
- Asperse
- Aspirant
- Aspirin
- Assegai
- Association of ideas
- Assurance
- Assuredly
- Astern
- Astonish
- Astonishing
- Astonishingly
- Astounded
- Astounding
- Astraphobia
- Astride
- At a stroke
- At all
- At any cost
- At any moment
- At every turn
- At first light
- At first sight
- At great length
- At least
- At most
- At night
- At odds
- 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