double bubble

noun4

1. •
   (slang) Overtime paid at twice the normal rate.

   • I feel you, man. But if you don't want the overtime, I'll work a double-bubble for you. Cool? — 2012
2. •
   The presence of two air-filled bubbles in the abdomen, often indicating various pathological conditions.
3. •
   A certain meeting of spherical surfaces, relevant to the double bubble conjecture.
4. •
   A fuselage formed from two conjoined hulls.