a pronoun, as English some, any, somebody, that leaves unspecified the identity of its referent.
Origin of indefinite pronoun
First recorded in 1720–30
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
grammar a pronoun having no specific referent, such as someone, anybody, or nothing
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012