index index /ˈɪndɛks/

noun

1. () 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  ( index number , indicant , index , indicator )
   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
     The rising temperature was an indicator of the approaching storm.
   The rising temperature was an indicator of the approaching storm.
   
2. () A numerical scale used to compare variables with one another or with some reference number  ( index )
   a numerical scale used to compare variables with one another or with some reference number
   
3. The finger next to the thumb  ( index , forefinger , index finger )
   the finger next to the thumb
    She used her index finger to scroll through the website on her phone
   She used her index finger to scroll through the website on her phone
   
   
4. An alphabetical listing of names and topics along with page numbers where they are discussed  ( index )
   an alphabetical listing of names and topics along with page numbers where they are discussed
   
5. A mathematical notation indicating the number of times a quantity is multiplied by itself  ( exponent , index , power )
   a mathematical notation indicating the number of times a quantity is multiplied by itself
     The dictator abused his power, oppressing the people.
   The dictator abused his power, oppressing the people.
   

verb

1. () List in an index  ( index )
   list in an index
   
2. Adjust through indexation  ( index )
   adjust through indexation
    The government indexes wages and prices
   The government indexes wages and prices
   
3. (publication) provide with an index  ( index )
   (publication) provide with an index
    Index the book
   index the book