1733, borrowing of Italian dilettante "lover of music or painting," from dilettare "to delight," from Latin delectare (see delight (n.)). Originally without negative connotation, "devoted amateur," the pejorative sense emerged late 18c. by contrast with professional.
Someone who is interested in the fine arts as a spectator, not as a serious practitioner. Dilettante is most often used to mean a dabbler, someone with a broad but shallow attachment to any field.