of unknown origin

phrase

—used to say that the source or cause of something is not known

a disease of unknown origin

Examples of of unknown origin in a Sentence

Recent Examples on the Web

The fire of unknown origin is considered the worst maritime disaster in modern California history. — City News Service, Daily News, 4 Mar. 2026

Early on, renovation workers discovered mysterious secret tunnels of unknown origin and use. — Richard Mize, Oklahoman, 27 Feb. 2026

Suddenly, an actual external parasite of unknown origin seemed to be its main topic, notwithstanding when it was written. — Chris Jones, Chicago Tribune, 9 Jan. 2026

Other rare items found at the site included a sheet-bronze boar’s head, originally from a military standard, as well as five shield bosses and an iron object of unknown origin. — Lianne Kolirin, CNN Money, 7 Jan. 2026

Rhymes for of unknown origin

• orogen