- Amatory
- Altered
- Alternately
- Alternating current
- Alternation
- Alternator
- Altitude
- Altruism
- Altruistic
- Alu
- Alumna
- Alumnus
- Alzheimer's disease
- Amalgamation
- Amassed
- Amative
- An acquatic plant
- An arrow
- An either or situation
- An electuary
- An expiatory spell
- An ignoramous
- An iron hand in a velvet glove
- An ornament
- An ornament for the neck
- Anabasis
- Andropogon
- Anechoic
- Anelectorde
- Anesthetized
- Angelic
- Angelica
- Angioplasty
- Angle
- Angle-hook
- Angled hook
- Anglo-catholic
- Anglo-saxon
- Angrily
- Angry man
- Angry outburst
- Anteroom
- Anthers
- Anthill
- Anthology
- Anthropic
- Anthropoid
- Anti-tank
- Antianxiety
- Antichthon
- Anticipate
- Anticipating
- Apheresis
- Aplasia
- Aplenty
- Apocalyptic
- Apolitical
- Apologue
- Apoplectic
- Apostatize
- Apostrophe
- Apotheosis
- Applicable
- Application window
- Applicator
- Appointed
- Appointed time
- Apposite
- Apposition
- Appraisal
- Appraised
- Appreciation
- Arboretum
- Arcane
- Arch-rival
- Archaeologist
- Archbishop
- Archery
- Architecturally
- Arrow-tip
- Art of arms
- Art of dancing
- Art paper
- Artefactual
- Artery
- Arthritis
- Artichoke
- Artichokes
- As per rule
- As poor as a church mouse
- As silent as a grave
- As well as
- As-much-as-one-can-do
- Asbestos
- Ascc
- Assembling
- Assertion
- Assessment
- Assets
- Assignation