-ist

American  

1. 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.

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-ist British  

suffix

1. (forming nouns) a person who performs a certain action or is concerned with something specified

   motorist

   soloist

2. (forming nouns) a person who practises in a specific field

   physicist

   typist

3. (forming nouns and adjectives) a person who advocates a particular doctrine, system, etc, or relating to such a person or the doctrine advocated

   socialist

4. (forming nouns and adjectives) a person characterized by a specified trait, tendency, etc, or relating to such a person or trait

   purist

5. (forming nouns and adjectives) a person who is prejudiced on the basis specified

   sexist

   ageist

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Etymology

Origin of -ist

Middle English -iste < Latin -ista < Greek -istēs; in some words, representing French -iste, German -ist, Italian -ista, etc., ≪ Latin < Greek, as above