- atoxic
- atresia
- atresia ani
- atretolemia
- atretorrhinia
- atrial standstill
- atrioventricular node
- atrophia
- atrophic inflammation
- atrophic kidney
- atrophic vaginitis
- atrophy
- attachment
- attachment apparatus
- attending staff
- attenuated virus
- attenuation
- attitudual reflex
- attraction sphere
- attrition murmur
- Au-antigenemia
- audiometer
- auditory bulb
- auditory center
- auditory threshold
- aural
- aural caculus
- aural nystagmus
- aural surgery
- auricle
- auricular arc
- auricular index
- auricular ligament
- auris external
- aurist
- autarcesis
- auto-antitoxin
- autoantibody
- autoantisepsis
- autochthonous
- autodiploidy
- autogenous inhibition
- autografting
- autohemotransfusion
- autohypnosis
- autoimmunedisease
- autoimmunity
- autolysis
- atylosis
- audible sound
- audiognosis
- audiogram
- auditory placode
- auditory vesicle
- auditorynerve
- aura
- aureomycin
- auricular glaucoma
- auricular groove
- auricular tubercle
- auriculopressor reflex
- auris internal
- aurogauge
- auscultate
- auscultation
- australia antigen
- ausystole
- autism
- auto-immune
- autoagglutination
- autocatalysis
- autocinesis
- autoclave
- autocollimating speetroscope
- autocytotoxin
- autodiagnosis
- autogamy
- autogenous vaccine
- autoimmune
- autoimmunization
- autoinoculation
- autointoxication
- autophyte
- autoploidy
- autoptic
- autosuggestibility
- autotoxic
- autovaccination
- auxetic growth
- auxin
- auxotox
- avascular
- avena fatua
- avena sativa
- average error
- automic imbalance
- autophobia
- autoplasty
- autopsy
- autosome