- Appendicitis
- Appertain
- Appetise
- Appetite
- Apple of the eye
- Appliance
- Application
- Applied mathematics
- Applied science
- Appositely
- Appositeness
- Apprehend
- Apprehension
- Apprehensively
- Apprise
- Apprize
- Approachable
- Approbate
- Approbatory
- Approve
- Approving
- April
- Apriori
- Apriorism
- Apropos
- Apse
- Aquatic animal
- Arabian sweat-meat
- Arapaima
- Arbitrage
- Arbitrarily
- Arbitrariness
- Arbitress
- Arboured
- Arcanum
- Arch
- Arch-work
- Archaeological
- Archaeology
- Archaic
- Archaism
- Archbishopric
- Archeology
- Archipelago
- Architecter
- Architecture
- Archive
- Archives
- Archivist
- Ardent
- Arduous
- Area manager
- Areal flood
- Aren't
- Argent
- Arguing
- Argumentation
- Aright
- Aril
- Arithmetically
- Arithmetician
- Arjuna
- Armband
- Armlet
- Armoured
- As and when
- Arms
- Army corps
- Aroma
- Aromatic
- Arpeggio
- Arrange
- Arrest
- Arrest attention
- Arrhythmic
- Arrived
- Arrogant
- Arrogate
- Arrow
- Arrow and bow
- Arrow point
- Arrow-root flower
- Arrow-root powder
- Arrow-root-flour
- Art director
- Arthropod
- Articulation
- Artificial respiration
- Artificialness
- Artist
- Artiste
- Artistic
- Artless
- Arts and part
- Arya race
- As clear as mud
- As far as possible
- As fit as a fiddle
- As if
- As memory serves