さ冴saえるeru
1.
To experience a heightened clarity in perception, where sights, sounds, and colors appear distinctly sharper and more vivid, often like on a cold, clear night.
2.
To exhibit heightened mental acuity or alertness, where one's thoughts and awareness are particularly sharp and focused, often described as having a clear mind.
3.
To show exceptional skill or proficiency, especially in a manner that stands out due to its brilliance or finesse, reflecting a high level of expertise.
4.
To be overcome with a sense of freshness and liveliness, often used in the context of one's expression or presence being vibrant and full of energy.
Example:
満月が空にさえている。