Amalgam: A mixture or blending of mecury with another metal or with an alloy

Ataxia: Unsteady and clumsy motion of the limbs or torso due to a failure of the gross coordination of muscle movements.

Biomagnification: The increase in concentration of an element or compound that occurs in a food chain across trophic levels

Bioaccumulation: The accumulation of a substance, such as a toxic chemical, in various tissues of a living organism

Cysteine: A naturally occurring, sulpfur-containing amino acid that is found in most proteins

Divalent mercury: a cation of mercury containing two fewer electrons

Docosahexaenoic acid: An omega-3 fatty acid essential to the growth and functional development of the brain

Dysarthria: Difficulty in articulating words, caused by impairment of the muscles used in speech. A speech impairment

Elemental mercury: A silvery-white poisonous heavy metal

Food chain: A succession of organisms in an ecological community that constitutes a continuation of food energy from one organism to another as each consumes a lower member and in turn is preyed upon by a higher member

Methionine: A sulfur-containing essential amino acid, C₅H₁₁NO₂S

Methylation: A process in which the hydrogen of the hydroxyl group of methyl alcohol is replaced by a metal

Methylmercury: (CH₃Hg⁺) organic form of mercury and the form of mercury that is most easily bioaccumulated in organisms; a neurotoxin.

Paresthesia: A sensation of tingling, pricking, or numbness of a person's skin. An indication of nerve damage.

Trophic level: A group of organisms that occupy the same position in a food chain