in·dex /ˈɪnˌdɛks/ 名詞
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In·dex n.; pl. E. Indexes L. Indices (░).
1. That which points out; that which shows, indicates, manifests, or discloses; as, the increasing unemployment rate is an index of how much the economy has slowed.
Tastes are the indexes of the different qualities of plants. --Arbuthnot.
2. That which guides, points out, informs, or directs; a pointer or a hand that directs to anything, as the hand of a watch, a movable finger or other form of pointer on a gauge, scale, or other graduated instrument. In printing, a sign [☞] (called also fist) used to direct particular attention to a note or paragraph.
3. A table for facilitating reference to topics, names, and the like, in a book, usually giving the page on which a particular word or topic may be found; -- usually alphabetical in arrangement, and printed at the end of the volume. Typically found only in non-fiction books.
4. A prologue indicating what follows. [Obs.]
5. Anat. The second finger, that next to the pollex (thumb), in the manus, or hand; the forefinger; index finger.
6. Math. The figure or letter which shows the power or root of a quantity; the exponent. [In this sense the plural is always indices.]
7. The ratio, or formula expressing the ratio, of one dimension of a thing to another dimension; as, the vertical index of the cranium.
Index error, the error in the reading of a mathematical instrument arising from the zero of the index not being in complete adjustment with that of the limb, or with its theoretically perfect position in the instrument; a correction to be applied to the instrument readings equal to the error of the zero adjustment.
Index finger. See Index, 5.
Index glass, the mirror on the index of a quadrant, sextant, etc.
Index hand, the pointer or hand of a clock, watch, or other registering machine; a hand that points to something.
Index of a logarithm Math., the integral part of the logarithm, and always one less than the number of integral figures in the given number. It is also called the characteristic.
Index of refraction, or Refractive index Opt., the number which expresses the ratio of the sine of the angle of incidence to the sine of the angle of refraction. Thus the index of refraction for sulphur is 2, because, when light passes out of air into sulphur, the sine of the angle of incidence is double the sine of the angle of refraction.
Index plate, a graduated circular plate, or one with circular rows of holes differently spaced; used in machines for graduating circles, cutting gear teeth, etc.
In·dex v. t. [imp. & p. p. Indexed p. pr. & vb. n. Indexing.]
1. To provide with an index or table of references; to put into an index; as, to index a book, or its contents.
n 1: a numerical scale used to compare variables with one another
or with some reference number
2: a number or ratio (a value on a scale of measurement)
derived from a series of observed facts; can reveal
relative changes as a function of time [syn: index number,
3: a mathematical notation indicating the number of times a
quantity is multiplied by itself [syn: exponent, power]
4: an alphabetical listing of names and topics along with page
numbers where they are discussed
5: the finger next to the thumb [syn: index finger, forefinger]
v 1: list in an index
2: provide with an index; "index the book"
3: adjust through indexation; "The government indexes wages and
[also: indices (pl)]