One who preaches, especially one who publicly proclaims the gospel for an occupation.
Alaska A fallen tree or log submerged in a river and creating a hazard for boats.
River navigation in America has its own lexicon, including words for hazards encountered in riverboat travel. Large uprooted trees that had drifted down the river and become stuck in the riverbed were sometimes known by their peculiar and dangerous characteristics. John McPhee writes for the New Yorker: "One kind . . . known as a sawyer, sawed up and down with the vagaries of the current . . . In the Yukon River, such logs—eternally bowing—are known as preachers. In the Mississippi . . . they were all snags."
[pree-cher] 
tʃər