- Ascariasis
- Ascendant
- Ascendent
- Asceticism
- Asecrtained
- Asexuality
- Ash-colour
- Ashore
- Ashy
- Asian palm civet
- Aside
- Ask for
- Assured
- Asthenia
- Astis
- Astonished
- Astraddle
- Astral body
- Astray
- Astrodome
- Astrolobe
- Astrologer
- Astute
- Astuteness
- Aswathi star
- Aswini devas
- At a gun point
- At will
- Atelophobia
- Atheism
- Atheistic
- Athri
- Athwart
- Atlantic
- Atmosphere
- Atom
- Atomic
- Atomic number
- Attendant
- Attending
- Attentive
- Attestation
- Attractiveness
- Atwitter
- Au courant
- Aunt
- Aureate
- Aurora
- Auster
- Austere
- Auteur
- Authenticate
- Authentication
- Authorised
- Authoritarianism
- Authoritative
- Autopsy
- Autotype
- Autumn
- Avacado
- Avarise
- Aver
- Average
- Avid
- Avidly
- Aviform
- Axle-tree
- Azolla
- Azure
- Agoraphobic
- Avoirdupois
- Amaranthus
- Antiquary
- Auctor
- A bad pill to swallow
- A bed of roses
- A bird in hand is worth two in the bush
- A bit much
- A blood relative
- A cardinal error
- A dead duck
- A dead luck
- A dear john letter
- A disciple who lodges with his preceptor
- A divine ministrel
- A dogs life
- A dry
- A false alarm
- A fiche
- A fish
- A floating voter
- A form of verse in which each line contains eight letters
- A golden parachute
- A good innings
- A good thing
- A grain of paddy
- A hollow laugh
- A host in himself
- A jam session
- A kings ransom