Definition of "plaint"

she seemed to repeat, though with perceptible resignation, her plaint of a moment before. ‘Your father, darling, is a very odd person indeed.’

1897, Henry James, What Maisie Knew

In the first paroxysm of his grief, Ingolfr exclaimed, (what sorrowing heart has not echoed his plaint?) that he could never more taste of joy.

1827, Maria Elizabeth Budden, Nina, An Icelandic Tale‎, page 11

His shriek was as feeble as the plaint of a grass-stalk in a storm.

1938, Xavier Herbert, chapter V, in Capricornia‎, page 75