Reduplicated names like 阳阳, 明明, 乐乐 are extremely common Chinese childhood nicknames — repetition softens the name and signals affection. 阳阳 specifically has been the official name of multiple giant pandas, including one gifted to Austria's Schoenbrunn Zoo (2003) and another sent to Mexico.
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As a classical adjective, 阳阳 can also mean 'bright / vigorous / self-satisfied' (per 《新华词典》), e.g. 《诗经》's 君子陽陽 'the gentleman is cheerful and content' — but in modern usage it functions almost exclusively as a name.
