Definition of "croaker"

There are croakers in every country, always boding its ruin.

1771, Benjamin Franklin, edited by John Bigelow, Autobiography of Benjamin Franklin‎, 1st complete English edition from Franklin's English Manuscript, J.B. Loppincott & Co., published 1868, part one, page 167

It is thought by many, and said by some, that this Republic has already seen its best days; that the historian may now write the story of its decline and fall. Two classes of men are just now especially afflicted with such forebodings. The first are those who are croakers by nature – the men who have a taste for funerals, and especially national funerals. They never see the bright side of anything, and probably never will.

1869, Frederick Douglass, Our Composite Nationality

"It is my advice," the speaker continued, "that we go easier upon the small men. On the day that they have all been driven out the power of this society will have been broken." Unwelcome truths are not popular. There were angry cries as the speaker resumed his seat. McGinty rose with gloom upon his brow. "Brother Morris," said he, "you were always a croaker..."

1915, Arthur Conan Doyle, The Valley of Fear

Frogs are also sensitive to vibrations through the ground, a footfall usually being sufficient to instil silence in a pond full of croakers.

1974, Clive Roots, Animals of the Dark, page 41

"Lungs," said McGuire comprehensively. "I got it. The croaker says I'll come to time for six months longer—maybe a year if I hold my gait.

Around 1900, O. Henry, Hygeia at the Solito