Answer: brightest

AnswerCrossword Clue
BRIGHTESTSuperlative for Sirius
brightestGiving an appearance of cheerful liveliness
brightestHaving a vivid color
brightestGiving out or reflecting a lot of light; shining
brightestBRIGHT, shining
brightest(of color) Vivid and bold
brightest(of someone's future) Likely to be successful and happy
brightest(of sound) Clear, vibrant, and typically high-pitched
brightestFull of light
brightest(of a person, idea, or remark) Intelligent and quick-witted
brightest(of a period of time) Having sunny, cloudless weather