RATIO
\ɹˈe͡ɪʃɪˌə͡ʊ], \ɹˈeɪʃɪˌəʊ], \ɹ_ˈeɪ_ʃ_ɪ__ˌəʊ]\
Definitions of RATIO
 2010  New Age Dictionary Database
 1913  Webster's Revised Unabridged Dictionary
 1919  The Winston Simplified Dictionary
 1920  A practical medical dictionary.
 1894  The Clarendon dictionary
 1919  The Concise Standard Dictionary of the English Language
 1846  Medical lexicon: a dictionary of medical science
 1871  The Cabinet Dictionary of the English Language
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The relation which one quantity or magnitude has to another of the same kind. It is expressed by the quotient of the division of the first by the second; thus, the ratio of 3 to 6 is expressed by / or /; of a to b by a/b; or (less commonly) the second term is made the dividend; as, a:b = b/a.

Hence, fixed relation of number, quantity, or degree; rate; proportion; as, the ratio of representation in Congress.
By Oddity Software

The relation which one quantity or magnitude has to another of the same kind. It is expressed by the quotient of the division of the first by the second; thus, the ratio of 3 to 6 is expressed by / or /; of a to b by a/b; or (less commonly) the second term is made the dividend; as, a:b = b/a.

Hence, fixed relation of number, quantity, or degree; rate; proportion; as, the ratio of representation in Congress.
By Noah Webster.
By William Dodge Lewis, Edgar Arthur Singer
By William Hand Browne, Samuel Stehman Haldeman
By James Champlin Fernald

A reason, a cause, an explanation, a mode or manner; as Ratio symptomatum, an explanation of the symptoms,  Ratio medendi, Genus curationis, Via curandi; the reason, mode or manner of cure.

Reason r. Medendi, see Ratio r. Symptomatum, see Ratio.
By Robley Dunglison

n. [Latin] Proportion ; rate ; degree ;in mathematics, the relation which one quantity or magnitude has to another of the same kind, as expressed by the quotient of the second divided by the first ;  fixed relation of number, quantity, or degree.