Occasionally accessory bones are found in the carpus, but of more than 20 such described bones, only four (the central, styloid, secondary trapezoid, and secondary pisiform bones) are considered to be proven accessory bones. Sometimes the scaphoid, triquetrum, and pisiform bones are divided into two.
perforce definition: by or through necessity; necessarilyOrigin of perforceMiddle English par force from OFr: see per and force...
Also found in: Encyclopedia, Wikipedia. perÂ·mitÂ·tivÂ·iÂ·ty. A measure of the ability of a material to interact with an electric field and become polarized by the field, so that the field within the material is weaker than the field in the absence of the material.