- Ants in ones pants
- Antsy
- Aphid
- Aphrodisiac
- Apiology
- Apnoea
- Apocryphal
- Apodyopsis
- Apogee
- Apology
- Apophenia
- Apophysis
- Apoptosis
- Aporia
- Apostasy
- Apostate
- Apprehensible
- Appropriately
- Appropriateness
- Appropriation
- Approver
- Approximate
- Appulse
- Appurtenance
- Apron
- Apsidiole
- Arbour
- Arc
- Arch-vault
- Archdeacon
- Archdiocese
- Archer
- Archetypal
- Archfiend
- Architect
- Architectonic
- Architectural
- Archway
- Arctic
- Arctic pole
- Ardent desire
- Ardent spirits
- Ardently
- Area
- Areca
- Areca leaves
- Areca palm
- Arecanut palm
- Arete
- Argot
- Argument
- Argumentative
- Argy-bargy
- Armoured soldiers
- Armourer
- Armpit
- Army comprising elephants
- Aroint
- Around
- Arranged
- Arranging
- Arrant
- Array of clouds
- Arrears
- Arresting
- Arrival
- Arriving
- Articulate
- Artificer
- Artificial insemination
- Artificiality
- Artistically
- Artistry
- Arts and crafts
- As
- As a first step
- As a man
- As proud as a peacock
- As regards
- As right as rain
- As safe as houses
- As soon as
- As soon as possible
- As the case may be
- As the crow flies
- As thin as a lath
- As usual
- Asafetida
- Asap
- Ascendancy
- Asphalt
- Asphyxia
- Asphyxiator
- Aspirate
- Aspiration
- Aspire
- Asr
- Ass
- Assailant
- Assassin