"one whose business is the decoration of dwellings or public edifices," 1700, agent noun in Latin form from decorate.
Entries linking to decorator
decorate v.
1520s, "deck with something becoming or ornamental, adorn, beautify," from Latin decoratus, past participle of decorare "to decorate, adorn, embellish, beautify," from decus (genitive decoris) "an ornament; grace, dignity, honor," from PIE root *dek- "to take, accept."
Earlier was decoren (early 15c.) with past-participle adjective decorat. Meaning "confer distinction upon by means of a badge or medal of honor" is from 1816. Related: Decorated; decorating.