Lottie Evanoff* once gave the word gwesk’wis for shelf fungus, which Coos people believed caused echoes. (Which is not unique to the Coos; the Quinalt thought since shelf fungi are ear shaped they caused echoes). She said it also meant people who mocked, mockers.
Today, while flipping though Jacobs notebooks looking for Hanis stories to transcribe I happened to notice the word gwesk’wis in a Milluk text, which was translated both times it appeared as ‘echo’. Now, many words are the same or very nearly so between Hanis and Milluk. So, I would guess that in Hanis gwesk’wis means, in addition to shelf fungus and mocker, echo. And in Milluk this word may also have referred to shelf fungus.
*Lottie mostly only spoke Hanis, but as a child she did speak Milluk and she did give JP Harrington a handful of Milluk words in his work with her in 1942.