Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android. Learn more here!


1. mixed astigmatism. 2. ametropia. 3. Symbol for the element americium.


against medical advice; Aerospace Medical Association; American Medical Association.


(a′mas) [Afrikaans] Variola minor.


alpha-Methylacyl-CoA racemase.

amacrine, amacrinal

(am′ă-krīn′, am″ă-krīn″ăl) [1an-macr- + Gr. is, stem -in-, fiber] Lacking a long process.


(ă-mal′găm) [L. amalgama fr. Gr. malagma, soft mass] An alloy used in dentistry to restore teeth. It is made predominantly of silver and mercury.

dental a. A dental restorative material made by mixing approx. equal parts of elemental liquid mercury (43% to 54%) and an alloy powder (57% to 46%) composed of silver, tin, copper, and sometimes smaller amounts of zinc, palladium, or indium. Dental amalgam has been used for over 150 years. A fraction of the mercury in amalgam is absorbed by the body, and people with amalgam restorations in their teeth have higher concentrations of mercury in tissues (including the blood, urine, kidneys, and brain) than those without amalgam fillings. In 1993 the Public Health Service of the U.S. Department of Health and Human Services published a report acknowledging that scientific data are insufficient to conclude that amalgam fillings have compromised health. There is no evidence that removal of amalgam fillings has a beneficial effect on health. A dental amalgam is colloquially called a silver amalgam or a silver filling.

silver a. A colloquial term for dental amalgam.


(ă-mal′gă-māt″) To combine mercury with silver, tin, and copper to produce amalgam. amalgamation (ă-mal″gă-mā′shŏn), n. amalgamator (ă-mal″gă-māt″ŏr), n.


(am″ă-nīt′ă, am″ă-nēt′ă) [Gr. amanitai, mushrooms] Any of various mushrooms of the genus Amanita, e.g., A. muscaria and A. phalloides. Most are toxic to the liver, hallucinogenic, or lethal.


(ā″mas′tē-ă) [a- + mast- + -ia] Absence of breast tissue. It may be due to a rare congenital anomaly or, more often, a bilateral mastectomy. SEE: amazia.


(ā″mas′tĭ-gōt″) [a- + mastigote] Leishman-Donovan body.


(am″ă-tok′sin) [ama(nita) + toxin] The chemical component of poisonous mushrooms that causes early onset of gastrointestinal upset. Liver failure follows about 36 hr later.


(ā″mā′zē-ă) [a- + Gr. mazos, breast] Absence of all breast tissue except the nipple. SEE: amastia.


[L. ambi-, on both sides] Prefix meaning both, both sides, or around.



Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.