The word is an eponym, named after the Biblical prophet Jeremiah, and is inspired by the tone of his surviving literary works, the Book of Jeremiah and the Book of Lamentations. The Book of Jeremiah prophesies the coming downfall of the Kingdom of Judah, and asserts that this is because its rulers have broken the covenant with the Lord:
But this thing commanded I them, saying, Obey my voice, and I will be your God, and ye shall be my people: and walk ye in all the ways that I have commanded you, that it may be well unto you.
But they hearkened not, nor inclined their ear, but walked in the counsels and in the imagination of their evil heart, and went backward, and not forward.
Since the day that your fathers came forth out of the land of Egypt unto this day I have even sent unto you all my servants the prophets, daily rising up early and sending them:
Yet they hearkened not unto me, nor inclined their ear, but hardened their neck: they did worse than their fathers.
Therefore thou shalt speak all these words unto them; but they will not hearken to thee: thou shalt also call unto them; but they will not answer thee.
But thou shalt say unto them, This is a nation that obeyeth not the voice of the LORD their God, nor receiveth correction: truth is perished, and is cut off from their mouth.
The Lamentations, similarly, lament the fall of the kingdom of Judah after the conquest prophesied by Jeremiah has occurred:
How doth the city sit solitary, that was full of people! how is she become as a widow! she that was great among the nations, and princess among the provinces, how is she become tributary!
She weepeth sore in the night, and her tears are on her cheeks: among all her lovers she hath none to comfort her: all her friends have dealt treacherously with her, they are become her enemies.
Judah is gone into captivity because of affliction, and because of great servitude: she dwelleth among the heathen, she findeth no rest: all her persecutors overtook her between the straits.
The ways of Zion do mourn, because none come to the solemn feasts: all her gates are desolate: her priests sigh, her virgins are afflicted, and she is in bitterness.
Generally, jeremiad, is given to moralistic texts that denounce a society for its wickedness, and prophesy its downfall. The jeremiad was a favorite literary device of the Puritans especially in sermons like Sinners in the Hands of an Angry God. Authors from Gildas to Robert Bork have had this label hung on their works. In contemporary usage, it is frequently pejorative, meant to suggest that the tone of the text is excessively pessimistic.