index /in′deks/ pl. indexes, indices [L, that which points out] , 1. index finger, the second digit of the hand, the finger adjacent to the thumb. Also called forefinger, index finger. 2. a unitless quantity, usually a ratio of two measurable quantities having the same dimensions, or such a ratio multiplied by 100. 3. a core or mold used in dentistry to record or maintain the relative position of a tooth or teeth to one another and/or to a cast, to ensure reproduction in the dental prosthesis of their original position. 4. a directory, in particular an alphabetized list of terms, each term accompanied by page numbers or other notations telling where it appears in a given work or set of works.
