What is the meaning of мен?

you

we

dog

I (first-person singular personal pronoun)

I (first-person singular personal pronoun)

I

I (first-person singular subject pronoun)

I

I

I (first-person singular subject pronoun)

First-person singular predicative particle, used after predicates.

alternative form of мене (mene) (the full form of the first-person singular pronoun in the accusative case, used as the direct object of a verb); me

alternative form of мене (mene) (the first-person singular pronoun in the prepositional case, used as the object of a preposition); me

I (first-person singular subject pronoun)

I (first-person singular nominative and disjunctive pronoun)

and (for nouns)

genitive plural of ме́на (ména)

I (first-person singular subject pronoun)

Forms the first-person singular predicative when used in conjunction with nouns, adjectives, and certain verb tenses, including the present-future and indefinite past.

Source: wiktionary.org