- a monotype printing machine
- atomic energy
- atomic pile
- all one's assets
- anew
- adipsia
- all steel coach
- alkaline residue food
- anacrotic pulse
- acid hydrolysis
- acid phosphatase
- acidic hydrogen
- acetoacetic acid
- acid house
- ablaut
- abominable snowman
- absolutistic
- a cameraman
- ammonia alum
- ammonium thiocyanate
- ammonium ichtho_ sulphonate
- ammonium reineckeate
- afferent loop syndrome
- accomplished through circumstances
- aplastic crisis
- a stable for elephants
- anticipated
- a water_fowl
- a water_well
- alcoholics anonymous
- aditus ad antrum
- aerophyte
- aphthous fever
- arthrogryposis
- a moderator
- addication
- acidophile
- athritic erosion
- appendicular
- androecium
- anaemia of scurvy
- antipruritic effect
- arrest of bleeding
- antiseptic fomentation
- arthus phenomenon
- acidified potassium dichromate
- allantoidoangiopagous twin
- acidotic condition
- alzheimer
- antasthmatic