UFO

noun3

1. •
   (informal) An "unfinished object" in knitting or other kinds of craft.

   • UFOs differ from WIPs in that a WIP is a project one is actively pursuing, while a UFO runs the risk of never getting finished. — 2007
2. •
   Initialism of unidentified flying object; (loosely) an alien spacecraft.

   • By that time not only the Australian press and public but also the Federal Government was agog with speculation as fresh UFO reports flowed in. — 1965
3. •
   Initialism of ultrared flattened object.