na̱'a̱g̱mnook [na̱'a̱/g̱m/*nook]
Compound composed of: na̱'a̱x  dress, nook  lie down
common noun. nightgown
Dm hoyu na̱'a̱mnook dziła dm nooki. I'm going to put on my nightgown before I go to bed.

Source: Draft Dictionary entry.