1839 as a term in philosophy, from impression + -ism. With reference to the French art movement, 1879, from impressionist. Extended 1880s to music (Debussy), literature, etc.
Entries linking to impressionism
impression n.
late 14c., "mark produced by pressure," also "image produced in the mind or emotions by something external," from Old French impression "print, stamp; a pressing on the mind" (13c.), from Latin impressionem (nominative impressio) "a pressing into, onset, attack," figuratively "a perception, mental impression," literally "a pressing into," from imprimere "press into or upon" (see impress (v.1)).
Meaning "act or process of making a mark upon the surface by pressing" is from early 15c.. Meaning "copy made by pressure from type or an engraving" is from 1550s; that of "printing of a number of copies, aggregate of copies printed at one time" is from 1570s. Meaning "belief, vague notion" (as in under the impression) is from 1610s.
-ism
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.