- Aplenty
- Apocalyptic
- Apolitical
- Apologue
- Apoplectic
- Apostatize
- Apostrophe
- Apotheosis
- Applicable
- Application window
- Applicator
- Appointed
- Appointed time
- Apposite
- Apposition
- Appraisal
- Appraised
- Appreciation
- Aptitude
- Aptness
- Aqua
- Aquamarine
- Aquaphobia
- Aquarius
- Aquatic
- Aqueous
- Aquifer
- Arabia
- Arabic
- Arak
- Arbitrary
- Arbor
- Arcot
- Arcturus
- 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