- Airport
- Airship
- Airstrip
- Airtight
- Aisle
- Aiyo
- Ajinomoto
- Alabaster
- Alarm clock
- Albeit
- Alchemist
- Alchemy
- Aleatory
- Alert
- Alfalfa
- Algal
- Algebric
- Algebrical elements
- Algol
- Algolagnia
- Alibi
- Alienable
- Alienated
- Align
- Aliment
- Alkali
- Alkalinity
- All along
- All clear
- All directions
- All in a maze
- All in good time
- All of a sudden
- All one knows
- All others
- All round
- All sorts
- All that
- All the same
- All the while
- All-knowing
- All-prevading
- Allege
- Allegro
- Allergen
- Allocate
- Allopathy
- Allotropism
- Allow
- Allowance
- Allurement
- Alluvion
- Almighty
- Almond
- Almound tree
- Almsgiving
- Almshouse
- Aloe plant
- Aloe spicata
- Aloe vera
- Aloof
- Alopecia
- Alpine
- Alright
- Alsatian
- Also
- Alstonia genus
- Altair
- Altar
- Alter
- Alternative
- Alternative energy
- Alternatively
- Alto
- Alum
- Always
- Am
- Amalgamate
- Amateur
- Amazement
- Amazon
- Ambiance
- Ambiguous
- Ambitious
- Amblyopia
- Ambulatory
- Ameliorative
- American football
- American indian
- Americanism
- Americium
- Amerindian
- Amiability
- Amiableness
- Amicus curiae
- Amid
- Ammunition
- Amniocentesis
- Among
- Amorality