- Air-pocket
- Air-pump
- Air-raid
- Airborne
- Aircraft
- Aircrew
- Albeit
- Alchemist
- Alchemy
- Aleatory
- Alert
- Alfalfa
- Algal
- Algebric
- Algebrical elements
- Algol
- Algolagnia
- Alibi
- Alienable
- Alienated
- Align
- All one knows
- All others
- All round
- All sorts
- All that
- All the same
- All the while
- All-knowing
- All-prevading
- Allege
- Allegro
- Allergen
- Alternative
- Alternative energy
- Alternatively
- Alto
- Alum
- Always
- Am
- Amalgamate
- Amateur
- American football
- American indian
- Americanism
- Americium
- Amerindian
- Amiability
- Amiableness
- Amicus curiae
- Amid
- Ammunition
- Amniocentesis
- Among
- Amorality
- 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
- 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