croaker

Etymology

croak +‎ -er

Noun

croaker (plural croakers)

1. One who croaks.
2. A vocal pessimist, grumbler, or doomsayer.
   • 1771, Franklin, Benjamin, John Bigelow, editor, Autobiography of Benjamin Franklin‎, 1st complete English edition from Franklin's English Manuscript. edition, J.B. Loppincott & Co., published 1868, OL 23279690M, part one, page 167:

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

   • 1915, Arthur Conan Doyle, The Valley of Fear

     "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..."

3. A frog.
4. A fish in the family Sciaenidae, known for the throbbing sounds they make.
5. (slang) A doctor.
   • Around 1900, O. Henry, Hygeia at the Solito

     "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.