Merriam-Webster Collegiate Dictionary - jewel

 I. noun  Usage: often attributive  Etymology: Middle English juel, from Anglo-French, diminutive of ju, jeu game, play, from Latin jocus game, joke — more at joke  Date: 13th century  1. an ornament of precious metal often set with stones or decorated with enamel and worn as an accessory of dress  2. one that is highly esteemed regarded the library as the ~ of the campus  3. a precious stone ; gem  4. a bearing for a pivot (as in a watch) made of crystal, glass, or a gem  • ~like adjective  II. transitive verb  (-eled or -elled; -eling or -elling)  Date: 1601  1. to adorn or equip with ~s  2. to give beauty to as if with ~s ; embellish