- Acquisition
- Acquittance roll
- Acrid taste
- Acridness
- Acrimony
- Acrobat
- Acronym
- Acrophobia
- Acrostic
- Acrylic
- Act
- Act a lie
- Act of god
- Act the fool
- Active programme
- Activism
- Activity
- Actor
- Acts of god
- Acuity
- Acute
- Acute angle
- Acutely
- Ad hominem
- Ad rem
- Ada
- Adage
- Adam
- Adamant
- Adaptable
- Adapted
- Add
- Add lustre to
- Add time
- Add up to
- Addable
- Added
- Addendum
- Adder
- Addicted to
- Addiction
- Additive
- Address
- Address book
- Address proof
- Adenoidal
- Adequate
- Adequately
- Adhered
- Adherence
- Adhesive tape
- Adjectivally
- Adjudicate
- Adjuration
- Adjust
- Admit
- Admittance
- Admitting defeat
- Admonition
- Admonitory
- Adon
- Adonis
- Adopted son
- Adoptionism
- Adorn
- Adrenal
- Adrift
- Adsorption
- Adulate
- Adulation
- Adult
- Adulterate
- Adulterated
- Adulteration
- Advanced
- Advantage
- Airing cupboard
- Airline
- Airlock
- Airman
- Airport
- Airship
- Airstrip
- Airtight
- Aisle
- Aiyo
- Ajinomoto
- Alabaster
- Alarm clock
- Albeit
- Alchemist
- Alchemy
- Aleatory
- Alert
- Alfalfa
- Algal
- Algebric
- Algebrical elements
- Algol
- Algolagnia