sleep on

What does sleep on mean?

To sleep on something or someone is to ignore, overlook, forget, be unaware of, or underestimate them.

Examples of sleep on

If you struggle with growing vegetables in the Florida heat, don’t sleep on okra. It’s a beginner-friendly, tough-as-nails crop that just keeps going no matter how hot it gets.
—Tonya Ashworth, The Florida Times-Union (Jacksonville, Florida), 20 June 2026

Kingston native and professional athlete Aaliyah Edwards is reminding young athletes not to sleep on the importance of sleep.
—Eva Sheahan, The Brockville (Ontario) Recorder & Times, 4 July 2026

Our running back, Rashawn, I’m telling you, man, y’all better watch out for him. He’s really slept on.
—Jordan Crisp, quoted in The Visalia (California) Times-Delta, 5 Oct. 2025

Where does sleep on come from?

This use of sleep on originated in African American English and has since become widespread. One of the earliest known uses appeared in the late 1980s in a song by pioneering rapper Spoonie Gee:

He’s very soft spoken, but the man hits hard / Don’t sleep on him and don’t drop your guard
—Spoonie Gee, “Mighty Mike Tyson,” The Godfather of Rap, 1987

And while the youth, as always, are at the forefront in creating the vocab, don’t sleep on the elders …
—Poet X, YSB Magazine, 31 Oct. 1995

… don’t sleep on this wonderful opportunity to gain hands-on experience and learn what it takes to work in the competitive field of entertainment.
—Raquel Boler, Essence, 1 Mar. 2001

How is sleep on used?

Sleep on is often used in recommendations/advice/warnings for someone not to underestimate/ignore someone or something, but not always:

Bonus points, too, for introducing this cynical music critic to Karim Ouellet’s delightful “L’Amour,” which I totally slept on when it was released in 2013 but now can’t get out of my head.
—Ben Rayner, The Toronto Star, 13 Oct. 2015