111th birthday
A ceremonial term for a 111th birthday, formed from the kanji 皇 (emperor) and 寿 (longevity). Extremely rare in everyday language; mostly encountered in traditional longevity celebrations or wordplay.
People who reach their 111th birthday are very rare.
The word 皇寿 is a special term for celebrating the longevity of a 111-year-old.
The kanji 皇 (emperor) can be decomposed into 白 (white) and 王 (king), and 白 can be read as 百 minus one (99), while 王 can be decomposed into 十 (10) and 二 (2), giving 99 + 12 = 111. This wordplay-based coinage is typical of traditional Japanese longevity terms.