alkylate - anatomist
- American Association of Dermatology
- American cockroach
- American College of Obstetricians and Gynecologists (ACOG)
- American College of Surgeons (ACS)
- American cutaneous leishmaniasis
- American Dental Association (ADA)
- American dog tick
- American hellebore
- American hookworm
- American Journal of Public Health
- American Law Institute formulation
- American Law Institute rule
- American leech
- American leishmaniasis
- American Medical Association (AMA)
- American National Standards Institute
- American Red Cross
- American Sign Language (ASL)
- American storax
- American tarantula
- American trypanosomiasis
- American Type Culture Collection
- American Type Culture Collection (ATCC)
- American visceral leishmaniasis
- americium
- amerism
- ameristic
- Ames
- Ames test
- AMet
- ametabolon
- ametabolous
- ametachromophil
- ametaneutrophil
- AMETHIST
- amethocaine
- amethopterin
- ametria
- ametriodinic acid
- ametrometer