noun, prefix
Used as a prefix or noun to refer to an unspecified person, place, or thing, often in formal or written contexts. Common in phrases like 某国 (a certain country) or 某氏 (a certain person).
某国の大統領が来日した。
The president of a certain country visited Japan.
某有名企業に勤めている。
I work for a certain well-known company.
pronoun
Archaic humble first-person pronoun used mainly by men. In modern Japanese, this usage is virtually obsolete and appears only in historical or stylized contexts.
See also: 某 (それがし)
某はその儀、承知仕った。
I am aware of that matter.