unsub
n.— «Button Up and four other “unsubs”—FBI shorthand for “unknown subjects”—together are thought to be responsible for more than 30 robberies, nearly one-third of the bank robberies committed in Washington since January.» —“Button Up Bandit, others hitting banks at rapid pace” by Sara Jean Green Seattle Times (Washington) May 12, 2006. (source: Double-Tongued Dictionary)
Further reading
Have you ever googled your own name and found someone else who goes by the very same moniker? There’s a word for that: googleganger. Plus, the language of hobbyists and enthusiasts: If you’re a beekeeper, perhaps you call yourself a...
She sells seashells by the seashore. Who is the she in this tongue twister? Some claim it’s the young Mary Anning, who went on to become a famous 19th-century British paleontologist. Dubious perhaps, but the story of her rise from seaside...