n, ‑fohr‑, twuhn-tee‑] 
Slang.| 1. | continually; constantly: They're together 24/7. |
| 2. | continual; constant: The manufacturer offers 24/7 customer support. |
Twenty-four hours a day, seven days a week: “This convenience store is open 24/7.” The term, which also appears as “24-7,” can be used figuratively to mean “with great time and effort”: “We worked on the design 24/7 in order to complete the work on time.” This phrase was coined in the late twentieth century.
