could care less

An alteration of couldn’t care less (which is first attested slightly earlier), either:^[1]

• by deliberate irony, or
• by hyponegation, perhaps influenced by forms such as “as if I could care less”, “no one could care less”, and “to know little (or nothing) and care less”.

• (Received Pronunciation) IPA^(key): /kəd kɛə ˈlɛs/
• (General American) IPA^(key): /kəd kɛ(ə)ɹ ˈlɛs/, /-ke(ə)ɹ-/

• Audio (General American):

  (file)

could care less (past perfect could have cared less)

1. (US, nonstandard) To not care at all; to have no concern or interest; to be apathetic.

   Synonyms: couldn't care less, not give a tinker's cuss, not give a tinker's damn

   • 1967, American Cooperation, Washington, D.C.: American Institute of Cooperation, →ISSN, →OCLC, page 235:

     Farmers knew that dead fish made plants go better. They could care less about why that happened. Scientists could not sleep until they found out why.

   • 1995 October 10, Thomas McGann (witness), Trademark Counterfeiting: Hearing before the Committee on the Judiciary, United States Senate, One Hundred Fourth Congress, First Session on S. 1136: A Bill to Control and Prevent Commercial Counterfeiting, and for Other Purposes  (Serial No. J-104-49), Washington, D.C.: U.S. Government Printing Office, published 1997, →OCLC, page 33:

     We do work [...] to develop some strength and testing standards so that the industry can be assured that safe products are being produced. The person who is doing a knockoff could care less about that, and so they will just produce the product with virtually no field or laboratory testing and ship it out.

   • 1999 June 23, Christopher Shays, Subcommittee Chairman, Combating Terrorism: Role of the National Guard Response Teams: Hearing before the Subcommittee on National Security, Veterans Affairs, and International Relations of the Committee on Government Reform, House of Representatives, One Hundred Sixth Congress, First Session  (Serial No. 106-32), Washington, D.C.: U.S. Government Printing Office, →OCLC, page 64:

     As someone who lives 30 miles away as the crow flies [...] from New York City, I could care less that New York City or New York State has a sense of jurisdiction. I would want to know whoever is most capable would be able to step in without any jurisdictional battle.

   • 2003, Donna Hill, If I Could (Dafina Books), New York, N.Y.: Kensington Publishing, →ISBN, page 58:

     Maybe it wasn't only time to move away from a job that was killing her spirit, but from people who could care less about her as a person, who saw her only as the good girl from next door, the one who would never do anything to upset anyone, who totally underestimated her.

• Some consider this expression erroneous because the literal meaning of this version is the opposite of the intended meaning.^[2] Others consider it acceptable because it is widespread and because omission of -n't is an instance of Jespersen’s Cycle, a linguistic process attested elsewhere in English and in other languages.^[3]

• “(I, etc.) could care less, colloquial phrase.” under “care, v.”, in OED Online ⁠, Oxford, Oxfordshire: Oxford University Press, 1888.
• “I (or he, she, etc,) could care less, phrase”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.