What is the meaning of 某?

certain (denoting that the speaker is referring to a specific person or thing that they do not want to name directly, implying that the listener should infer the identity of the referent)

a certain person or thing; a so-and-so

I; me

someone; somebody; a certain person

I; me

chữ Hán form of mỗ (“such-and-such (placeholder)”)

chữ Hán form of mỗ (“ I”)

Source: wiktionary.org