Merriam-Webster's Collegiate® Dictionary, 11th Edition
COFFER
I. noun
Etymology: Middle English coffre, from Anglo-French, ultimately from Latin cophinus basket, from Greek kophinos
Date: 13th century
chest , treasury , funds, a recessed panel in a vault, ceiling, or soffit,
II. transitive verb
Date: 14th century
to store or hoard up in a coffer, to form (as a ceiling) with recessed panels