- Adp
- Airily
- 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
- All one knows
- All others
- All round
- All sorts
- All that
- All the same
- All the while
- All-knowing
- All-prevading
- Allege
- Allegro
- Allergen
- Almsgiving
- Almshouse
- Aloe plant
- Aloe spicata
- Aloe vera
- Aloof
- Alopecia
- Alpine
- Alright
- Alsatian
- Also
- Alstonia genus
- Altair
- Altar
- Alter
- Amazement
- Amazon
- Ambiance
- Ambiguous
- Ambitious
- Amblyopia
- Ambulatory
- Ameliorative
- Amorous
- Amortize
- Amperage
- Ampere
- Amplifier
- Amplify
- Amply
- Ampoule
- Amputate
- Amuck
- Amusement
- Amusements
- An
- An abuse
- An agonist
- An arm and a leg
- An ascetic
- An ayurvedic treatment
- An edible snail
- An even chance
- An item in phyrotechnics
- An oil-press
- An old head on young shoulders
- Anabolism
- Anacardium occidentale
- Anaemia
- Anaesthetist
- Analogous
- Analogy
- Analysable
- Analyse, analyze
- Anandavardhana
- Anarchism
- Anarchist
- Anasarca
- Anecdote
- Anemia
- Anencephalus
- Anent
- Anesthetic
- Anesthetist
- Aneurysms
- Anger
- Angina
- Angiras
- Anglicize
- Angling
- Anglo
- Anglophone
- Angora
- Angry
- Annihilated
- Annihilation
- Annualized