1850 in reference to an artist who seeks to portray the emotional experience of the subject, from expression (which was used in the fine arts by 1715 with a sense "way of expressing") + -ist. Modern sense is from 1914, from expressionism (from 1908 as an artistic style or movement). As a noun from 1880. Related: Expressionistic.
expressionist art
expostulation
exposure
expound
express
expression
expressionist
expressionless
expressive
expressly
expresso
expressway