second in rank; second sign of the Chinese calendar
Refers to the second of the ten heavenly stems (十干), used in the traditional Chinese sexagenary cycle. Often appears in compound terms like 乙丑 (きのとうし) or 乙未 (きのとひつじ). As a standalone word, it is primarily a historical or calendrical term.
The second of the ten heavenly stems is 乙 (きのと).
今年は乙未の年です。
This year is the year of 乙未 (きのとひつじ).
From the Chinese heavenly stem system. The reading きのと is a native Japanese reading (kun'yomi) combining 木 (き, 'wood') and 弟 (と, 'younger brother'), reflecting the element and order. The kanji 乙 is used for its meaning as the second stem.