郭璞
Classical Chinese and Japanese literature contains many Chinese characters that feature only once in the corpus, and their meaning and pronunciation has often been lost. Known in Japanese as , literally "lonely characters", these can be considered a type of "hapax legomenon". For example, the "Classic of Poetry" (c. 1000 BC) uses the character 篪 exactly once in the verse "伯氏吹埙，仲氏吹篪", and it was only through the discovery of a description by Guo Pu (276–324 AD) that the character could be associated with a specific type of ancient flute.