This is the 9122nd most frequent Japanese word.
為永
"為永" (Tamenaga) is a Japanese surname.
In this sentence, '為永' is used as a proper noun referring to a person's surname.
彼の名字は為永です。
His surname is Tamenaga.
Here, '為永' is part of the author's name, indicating his identity in historical context.
『為永春水』は江戸時代の文学作品です。
'Tamenaga Shunsui' is a literary work from the Edo period.
In this sentence, '為永' refers to the family name, used in the context of genealogical study.