could care less
Definition from Wiktionary, the free dictionary
- (idiomatic, US) Lacking interest; having apathy towards.
- 1936, The New Yorker, Volume 12, Part 1 
- "Whether they go to Heaven or to Hell, they could care less. Because Nigeria is a hell already."
- 1947, Schwengel (quoted in Hearings before the Subcommittee on Public Buildings and Grounds of the Committee on Public Works, House of Representatives, U.S. Govt. Print. Off.) 
- I discovered in my community, for instance, they could care less about water pollution in the Mississippi River and yet it just affects hundreds of thousands of people…
- 1967, American Institute of Cooperation, American Cooperation, 
- 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, Orrin Hatch (ed.), Trademark Counterfeiting: Hearing Before the Committee on the Judiciary, U.S. Senate 
- 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...
- 1999, Christopher Shays, Combating Terrorism: Role of the National Guard Response Teams 
- 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.
- 2003, Donna Hill, If I Could (p.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.
- 1936, The New Yorker, Volume 12, Part 1