Ist (noun) Definition, Meaning & Examples

a suffix of nouns, often corresponding to verbs ending in -ize or nouns ending in -ism, that denote a person who practices or is concerned with something, or holds certain principles, doctrines, etc.: apologist; dramatist; machinist; novelist; realist; socialist; Thomist.

suffix

a person who performs a certain action or is concerned with something specified
a person who practises in a specific field
a person who advocates a particular doctrine, system, etc, or relating to such a person or the doctrine advocated
a person characterized by a specified trait, tendency, etc, or relating to such a person or trait
a person who is prejudiced on the basis specified