- Airlock
- Airman
- Airport
- Airship
- Airstrip
- Airtight
- Aisle
- Aiyo
- Ajinomoto
- Alabaster
- Alarm clock
- 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
- Anatomist
- Anatomy
- Ancestor
- Ancestry
- Ancient story
- Ancillary
- And a half
- And that's flat
- And the like
- And then
- And things
- And what is more
- Andirons
- Androcentricity
- Andropause
- Anhydride
- Anima
- Animadvert
- Animal
- Animalcule
- Animals
- Animated
- Animator
- Animosity
- Aniseed
- Ankle
- Anklet with bells
- Annals
- Anonymous letter
- Anorexic
- Another key
- Answer back to
- Answer for
- Antechamber
- Antennae
- Antepenultimate
- Anticipation
- Anticipative
- Antihelmintic
- Antihistamines
- Antilog
- Antilogarithm
- Antimacassar