冴える

What does 冴える mean in English?

1. to be clear (of a sight, sound, colour, etc.); to be bright; to be vivid; to be crisp(v1, vi)
2. to be clear-headed; to be alert; to be on the ball; to be wide awake(v1, vi)
3. to look upbeat; to be perky; to be cheerful(v1, vi)
4. to master (a skill); to excel at; to cleanly execute(v1, vi)
5. to be satisfying(v1, vi)
6. to become frigid; to become intensely cold(v1, vi)