dates of birth and death unknown
A fixed phrase used in biographical contexts, similar to 生没年不詳. Often seen in historical or academic descriptions.
See also: 生没年不詳
This painter's dates of birth and death are unknown, but many works remain.
Synonymous; 不詳 is more common than 未詳 in this phrase, but both are used.
Compound of 生没年 (dates of birth and death) and 未詳 (unknown, not yet detailed).