dingus

noun3

1. •
   (US, informal) A gadget, device, or object whose name is either unknown, forgotten, or omitted for the purpose of humor.

   • "He took the this-is-unheard-of-but-not-really-serious-of-course attitude of a street fakir whose mechanical dingus flops during a demonstration." — 1929
2. •
   (informal, disapproving) A foolish, incompetent, or silly person.

   • I just lost my keys again. Now I feel like a dingus.
3. •
   (slang, vulgar) The penis.

   • "He got mad at me because his dingus wouldn’t come up for him — too drunk, I guess. […] — 1970