AAP 1 American Academy of Pediatrics, a professional organization for physicians who treat infants, children, adolescents, and young adults. 2 American Academy of Pedodontics, a professional organization. 3 American Academy of Periodontology, a professional organization. 4 American Association of Pathologists, a professional organization.
AAOS American Academy of Orthopaedic Surgeons, a professional organization. See also orthopaedics.
AAO 1 American Association of Ophthalmology, a professional organization. 2 American Association of Orthodontists, a professional organization. 3 American Academy of Otolaryngology, a professional organization.
AAFP 1 American Association of Family Physicians, a professional organization for physicians who treat both children and adults. 2 American Academy of Family Physicians, a professional organization for physicians who treat both children and adults.
AAAS American Association for the Advancement of Science, a professional organization that publishes the weekly journal Science.
AA 1 Alcoholics Anonymous. 2 Amino acid.
a- Prefix indicating the absence or depletion of something: for example, aphagia (not eating) or aphonia (voiceless). The related prefix an- is usually used before a vowel, as in anemia (without blood) and anoxia (without oxygen).
A In genetics, adenine, a member of the adeninethymine (A-T) base pair in DNA.