Denshi Jisho — Online Japanese dictionary

乃 の possessive particle
Particle, Archaism 
乃公 おれ I; me (rough or arrogant-sounding first-person pronoun, formerly also used by women)
Pronoun, No-adjective, Male term or language 
乃至 ないし 1: from ... to; between ... and;
2: or
Common word, Conjunction 
乃父 だいふ father
Noun 
乃ち すなわち that is; namely; i.e.
Adverb, Conjunction, Usually written using kana alone 
乃公 だいこう I; me (rough or arrogant-sounding first-person pronoun, formerly also used by women)
Pronoun, No-adjective, Male term or language 
乃公 ないこう I; me (rough or arrogant-sounding first-person pronoun, formerly also used by women)
Pronoun, No-adjective, Male term or language 

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