Verbs in the Coos Bay and Siuslaw languages can be very playful – reduplication (this is repeating part or all of the verb stem), prefixes and suffixes, can make complex words.
Annie Miner Peterson mentioned a dance and ceremony that apparently marked the winter solstice, that she called tk’alis biinats’ in Hanis, and q’wole’es biinats’ in Milluk – in either language it means sun goes back, with biinats’ meaning ‘go back’ in either language.
It struck me suddenly that the bii- part of ‘go back’ looked familiar. I recalled the verb ‘to go home’ was recorded in several places as piiʰ-, bii-, or piiˣ-, and the like. So you get the straightforward piiʰpii, he/she went home, to pii’iiyat, he/she took it home. The word biinats’ looks like it has the same root as ‘to go home’. Now, the –ts’ is probably –ts, the Hanis transitive suffix that often also is a general verbal suffix. So, if the root of biinats’ is ‘to go home’. What is the n in the middle? There is a suffix that Leo Frachtenberg identified in his grammar as a distributive – meaning, distributing the action. But a contemporary linguist, Marianne Mithun, identifies these suffixes as reciprocals or iteratives -this meaning, an action that goes on and on for a long time. The problem is this suffix is usually identified as –nii or –nei, not -na as it appears in biinats’.
So the n in biinats’ may or may not be this distributive or iterative suffix. But if nothing else, I still thing the roots of pii/bii to go home, and biinats’ to go back are related.