The basal portion or proximal end of a projectile or knife blade which was designed for attaching or lashing or adhering to a shaft or handle for use. The characteristics of this portion of a projectile/blade artifact are critical for accurate identification. Such attributes as notching, fluting, thinning, grinding or stemming are key diagnostic elements for point typology. In most cases, a specimen can be classified if only this portion of the example is found intact, while the absence of this part will make a specific analysis and typology effort difficult or impossible.
Source: LITHICS-Net, Glossary of Lithics Terminology