Bright
Part of speech: adjective
Definition: Visually dazzling; luminous, lucent, clear, radiant; not dark. Intelligent, brilliant. Vivid, colourful, brilliant. Happy.
Part of speech: noun
Definition: An artists brush used in oil and acrylic painting with a long ferrule and a flat, somewhat tapering bristle head. A neologism intended as a positive-sounding umbrella term to describe various kinds of non-religious and non-superstitious people. (There is a Wikipedia article on this usage.)
Example sentence: The future is as bright as the promises of God.
Brightly
Part of speech: adverb
Definition: In a bright manner.
Example sentence: It was the late Dr. Mahendra Lal Sircar who, by founding the Indian Association for the Cultivation of Science, made it possible for the scientific aspirations of my early years to continue burning brightly.