coffer, in architecture, a square or polygonal ornamental sunken panel used in a series as decoration for a ceiling or vault. The sunken panels were sometimes also called caissons, or lacunaria, and a coffered ceiling might be referred to as lacunar.

What does the word coffer mean?

Definition of coffer (Entry 2 of 2) transitive verb. 1 : to store or hoard up in a coffer coffered his military memorabilia. 2 : to form (something, such as a ceiling) with recessed panels A ceiling that is coffered will bring an added dimension to a large room.

Why is it called a coffer?

coffer (n.)

mid-13c., "box or chest used for keeping valuables," from Old French cofre "a chest" (12c., Modern French coffre), from Latin cophinus "basket" (see coffin). Hence coffers, in a figurative sense, "a treasury; the wealth and pecuniary resources of a person, institution, etc.," late 14c.