Noun
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
Source: WordNetCarroll's book may possibly have been the first novel to feature H.D., but it seems unfair to give him credit for creating a character that has its own Roud Folk Song Index number. Source: Internet
In the CII schema, each pigment has a generic index number that identifies it chemically, regardless of proprietary and historic names. Source: Internet
The university uses an admissions index number that gives equal weight to GPA and ACT/ SAT scores. Source: Internet