The short answer

Throw in the sponge means to concede or stop struggling. The unusual plural in this page’s address, throwing in the sponges, is understandable, but the historical entries checked here record a single sponge. If you are quoting an old source or discussing the history, keep its actual wording: throw up the sponge or throw in the sponge. In ordinary writing, throw in the towel will be clearer.

What the dated record shows

John Camden Hotten’s 1860 Dictionary of Modern Slang, page 224, defines throw up the sponge as submitting or ending a struggle. It connects the phrase directly with the sponge used to clean a prizefighter’s face and a signal that the fight is over. This is a dated dictionary record of the wording and its explanation, not proof of the first time anyone said it.

Phrase Finder reports an earlier 26 January 1845 Era boxing report in which a sponge was thrown up as a sign of submission, citing Green’s Dictionary of Slang. We have checked Phrase Finder’s account, but not the original newspaper image; the 1845 wording should therefore be treated as a reported quotation. Etymonline dates “throw in the sponge” to 1860 and identifies prizefighting, while its towel entry dates a figurative towel use to 1901. These references support sponge wording appearing in the written record before the familiar towel form; they do not establish a single inventor or an exact moment of replacement.

Why the forms differ

Throw up the sponge is the form Hotten printed. Throw in the sponge is the later dictionary headword used for the same surrender idea. Throw in the towel became the common modern wording. The preposition and object changed, while the public act of concession stayed recognizable. For the full towel history, including its own dated evidence, see the separate towel guide.

The plural sponges can sound like a playful variation, especially in a sentence about several people giving up. The checked historical entries do not establish it as the traditional form or measure how often people use it. A reader editing a quotation should not silently change sponge to sponges.

Which wording fits today?

  • Clear everyday choice: “After three attempts to repair the old printer, we threw in the towel.”
  • Historical or deliberately old-fashioned: “The report said the boxer’s corner threw up the sponge.” This describes the older boxing signal rather than treating the phrase as a fresh invention.
  • Awkward in a formal memo: “The board threw in the sponges.” Unless you intend the unusual wording, write “ended the project” or “conceded.”

The expression implies a struggle or contest that someone decides to stop. It does not fit a routine choice such as leaving a party at the planned time. Stopping can be prudent, so the idiom does not by itself judge the decision as cowardly.

Correction, 27 September 2026: An earlier version included surgical-sponge material unrelated to this idiom. It has been removed from this public guide, and the older boxing wording is now supported with dated source notes.

Source notes