wikipedia

The term "Jesus clip" is a comical reference given to it due to its tendency to come loose and launch itself at high speed while removing or installing it, often leading to the remark "Oh Jesus, where did it go man?"

A circlip (a portmanteau of "circle" and "clip"), also known as a C-clip, snap ring, or Jesus clip, is a type of fastener or retaining ring that consists of a semi-flexible metal ring with open ends that can be snapped into place into a machined groove on a dowel pin or other part to permit rotation but to prevent axial movement.