I. noun
1. : a composition of formal pattern in painting, sculpture, music, or literature
an autobiographical set piece
thrilling effect of … any of Shakespeare's great set pieces — W.S.Maugham
the set pieces, too — the cathedrals and galleries and parks and palaces … come alive — Mitchell Goodman
2.
a. : a flat cut to the silhouette of a building, tree, mountain, or some other object required in a stage setting
b. : a piece of constructed scenery
3. : a framework on which fireworks are so arranged as to form a design on burning
4. : a precisely planned and conducted military operation
II. noun
: a scene, depiction, speech, or event that is obviously designed to have an imposing effect