forty-eighth year H12 of the 60 year cycle, e.g. 1971 or 2031
cf 辛亥革命[Xin1 hai4 Ge2 ming4], Xinhai Revolution of 1911
Definitions (Wiktionary)
noun
The forty-eighth term of the Chinese sexagenary cycle, sometimes glossed as "Metal Pig" from its associated terms in the Chinese elements and zodiac.