Definition of "purling"

They have sometimes caused an high steepy mountaine to arise in the midst of the sayd Amphitheaters, all over-spred with fruitfull and flourishing trees of all sortes, on the top whereof gushed out streames of water as from out the source of a purling spring.

1603, Michel de Montaigne, translated by John Florio, Essays, III.6

"Thank Heaven," cried Henrietta, laughing, "you do not, even in fancy, turn me into a shepherdess, with sheep on one side, and a purling brook on the other."

1837, L[etitia] E[lizabeth] L[andon], chapter IV, in Ethel Churchill: Or, The Two Brides. […], volume I, London: Henry Colburn, […], page 44

[Thomas Jefferson] was up near the source of the River of America, near the Three Forks, while we are downstream from New Orleans in a broad, deep, incredibly powerful river that often feels more like a sewer than a purling mountain stream.

2018, Clay S. Jenkinson, Jefferson's Second American Revolution, in: The Jefferson Watch, December 18 2018