Menyaachamlly: "You all", indefinite pronoun. This is the second-person or "you" form of Tiipay nyaachamlly, "everyone, everything". Robertson's version seems to have a long "aa" in the first syllable, although the word is transcribed as nyachamlly in other sources.
In Tiipay, nyachamlly "everyone, everything" can also be said as, nyacham, cham, and chamlly.
'Iipay equivalent is nyaamat, which can also be made into menyaamat, "you all".