Terms derived from Greek
- abacus
- Abaddon
- abyss
- acolouthia
- acolyte
- acrostic
- aeon
- aer
- aesthetics
- agape feast
- agapetae
- Agios O Theos
- agnoetre
- allegory
- alms
- alpha and omega
- altar canopy
- ambo
- amphitheater
- amphorae
- amphorre
- Anabaptists
- anagnostes
- analecta
- Analepsis
- analogy
- anaphora
- anarchy
- Anastasis
- anathema
- anatomy
- anchor
- anchor cross
- anchoress
- anchorhold
- anchorite
- angel
- anthropology
- anthropomorphism
- anti-paedobaptists
- Antidicomarianites
- antimensium
- antinomies
- antiphon
- antipodes
- antitype
- apo stella
- apocatastasis
- apocrypha
- Apodeipnon