Sny

“And did you kill it?” “I did, for they’re a nuisance. The place is fair snied wi’ ‛em.”

Source: wiktionary

1893, Mark Twain, Tom Sawyer Abroad, Tom Sawyer, Detective and Other Stories (1896), page unknown “Well, Mars Tom, my idea is like dis. It ain’t no use, we can’t kill dem po’ strangers dat ain’t doin’ us no harm, till we’ve had practice — I knows it perfectly well, Mars Tom — ‛deed I knows it perfectly well. But ef we takes a’ ax or two, jist you en me en Huck, en slips acrost de river to-night arter de moon’s gone down, en kills dat sick fam’ly dat’s over on the Sny, en burns dey house down, en —”

Source: wiktionary

The word snye, sny or snie has been used for many years to describe a channel behind an island, with slack current or partly dried, or some such similar feature.

Source: wiktionary