one day

idiom

1

: at some time in the future

One day, it'll happen. You'll see.

People may one day be able to take vacations to the moon.

2

: on a day in the past

I went to her house one day and had lunch with her.

One day, we had a terrible argument.

Examples of one day in a Sentence

Recent Examples on the Web

In addition to satellites, could iPhones one day receive 5G from an unmanned high-altitude plane or balloon? —PC Magazine, 11 Sep. 2025

Keep prepared Snickers salad in an airtight container in the refrigerator for up to one day. —Jasmine Smith, Southern Living, 11 Sep. 2025

Breakthroughs like this new discovery give the field fresh momentum, offering hope that phages could one day join or even replace antibiotics in treating stubborn infections. —Alice Gibbs, MSNBC Newsweek, 11 Sep. 2025

If consumers continue to lose financial ground and the federal government continues to overspend, one day the government may have to choose between helping victims of the latest disaster or paying out Social Security benefits (or other program payments). —Mike Patton, Forbes.com, 11 Sep. 2025

Rhymes for one day

• aaa
• adonais
• alleyway
• alumnae
• anime
• anyway
• arete
• attache
• baa
• beaujolais
• bouvier
• breakaway