A CHAH-mooz-ee was an ancient healing symbol of the "Sky Spirits", the Rubber Tree People, and the more traditional descendants of the Rubber Tree People, drawn on various natural objects as a blessing to the land, such as on the ground for scaring it with a campfire, or a piece of a tree that was cut down for firewood. It was also drawn on the ground during greetings as a sign of respect.
In 2372, Chakotay, a descendant of the Rubber Tree People, found a CHAH-mooz-ee on a moon in the Delta Quadrant that had been visited by the Sky Spirits. On the Spirits' planet, not knowing his tribal language and without a universal translator, he used the word to show the aliens that he had some connection to them. (VOY: "Tattoo")
A stone with a CHAH-mooz-ee on it was also in Chakotay's medicine bundle. He often started rituals involving it by taking the stone and addressing it by his name. (VOY: "The Cloud")
The CHAH-mooz-ee symbol was designed by Rick Sternbach. According to the Star Trek Encyclopedia (2nd ed., p. 70), "Rick says he based the design on a map of the Milky Way galaxy, and the V lines may – or may not – suggest the paths of various wormholes and other spatial phenomena across the galaxy."
The CHAH-mooz-ee symbol inspired the design of a mandala on the wall of Chakotay's quarters, which was also meant to represent a hidden map of the galaxy. Rick Sternbach commented, "The thought occurred to me that because their ancestors had contact with the alien 'Sky Spirits,' the Rubber Tree People had some knowledge of travel throughout the Galaxy. So I figured, 'Why not work some of those elements into the design?' [....] The design for the stones [in the CHAH-mooz-ee] had already been approved, and they'd accepted the idea of the spirals and the straight lines. That could be interpreted in any number of ways, but when you took it with the wall hanging you could see it was a map of the Galaxy, which showed the Bajoran wormhole and Voyager's path to the Delta Quadrant." (Star Trek: The Magazine Volume 2, Issue 10, p. 112)