Metal or coloured moulded testicles attached to the back of your truck, possibly present to demonstrate to the world the size of your actual testicles, or to compensate for a certain lack in that department...
Plastic or metal reproductions of testicles (either human or bull) that hang from a trailer hitch. They come in numerous colors and are usually found on pickup trucks or SUVs.
When a woman has to put her trust in the man in her life, no matter how inept, to handle the power tools because he has the testicles. Literally she put her faith in him because he has the testicles