Merriam-Webster Collegiate Dictionary - umbrella

 I. noun  Etymology: Italian ombrella, modification of Latin umbella, diminutive of umbra  Date: 1611  1. a collapsible shade for protection against weather consisting of fabric stretched over hinged ribs radiating from a central pole; especially a small one for carrying in the hand  2. the bell-shaped or saucer-shaped largely gelatinous structure that forms the chief part of the body of most jellyfishes  3. something which provides protection: as  a. defensive air cover (as over a battlefront)  b. a heavy barrage  4. something which covers or embraces a broad range of elements or factors decided to expand…by building new colleges under a federation ~ — Diane Ravitch  II. transitive verb  (-laed; -laing)  Date: 1834 to protect, cover, or provide with an ~