purity; pure-heartedness
Describes a person's character as pure, sincere, and untainted. Often used in literary or formal contexts.
I was moved by his pure-hearted character.
Devote oneself to art with a pure spirit.
one's best; the best one can do · with all one's might; as hard as possible
The exact derivation is uncertain. The kanji 精 (refined, spirit) and 一 (one, single) suggest a meaning of 'single-minded purity' or 'unified spirit'.