The suffix -ist, which comes from the Greek suffix -istes, forms agent nouns, that is, nouns that denote someone who does something. Although -ist frequently forms agent nouns from verbs ending in -ize or nouns ending in -ism, it has also come to be combined with words that do not end in -ize or -ism. In fact in some cases -ist can be used much like the suffix -er. In pairs such as conformer/conformist, copier/copyist, and cycler/cyclist, -ist and -er may be used interchangeably.
