> use the adjectives to figure it out..
> ...
> ...
> I discount #2. So does {ngab} mean to be in agreement,
> to have similar sounds, or to be resonant?
I don't know why you discount it, since that's exactly what Dr. Okrand said it referred to.
https://www.kli.org/activities/qepmey/past-qepamey/qepa-chamah-hutdich/new-words/