Noun: A flaccid prosthetic in the size and shape of a penis, used to give the look and feel of typical male anatomy.
As a term, Packer represents a type of prosthetic that does nothing other than act as a flaccid “bulge maker’. Unless modified, packers are not STPs, can not be used for sexual intercourse, or oral stimulation. If the prosthetic lists packing as one of their models features, this means that the bulge of the item is small enough, and the density is soft enough, to be considered a packing device.
For example, “Pack and Play” is a common term for a prosthetic that can be used as both a packing tool and a sexual prosthetic.