Definition, synonyms and related words
plural of index
"The study guide included several useful indexes at the back of each textbook."
Third-person singular simple present indicative form of index
"The stock market indexes rise sharply when investors feel optimistic about the economy."
In plain English: To index means to organize information so it can be found easily, like putting books on shelves by their titles.
"The library indexes thousands of books every year to help patrons find them easily."