noun
A, B and C; first, second and third
Used for three-grade classification, often in formal or grading contexts. The three characters represent the first three of the ten Heavenly Stems, used here as ordinal markers.
成績は甲乙丙で評価された。
The results were graded as A, B, and C.
この書類は甲乙丙の三種類に分類される。
These documents are classified into three types: A, B, and C.
甲 alone means 'first' or 'A', the top grade in a classification.
From the first three of the ten Heavenly Stems (甲, 乙, 丙), traditionally used for ordering and grading.