noun
A, B, C and D; first, second, third and fourth
Used to list or rank four items in order, often in formal or technical contexts such as grading, classification, or sequential labeling.
成績を甲乙丙丁で評価する。
Grades are evaluated as A, B, C, and D.
候補者を甲乙丙丁の順に並べた。
The candidates were ranked in order of first, second, third, and fourth.
From the first four of the ten Heavenly Stems (十干), used as ordinal markers in classical Chinese and adopted into Japanese for grading and ordering.