Sharp, barbed; not dull.
Directed negatively at a person or topic.
Having a relevance to the matter at hand: pertinent, relevant.
That has a named, but otherwise arbitrary, point (called the basepoint) that remains unchanged during subsequent discussion and is kept track of during all operations.
In animals, having a coat pattern with points, that is, darkening of the extremities.
Having spines, spiny.
Having a certain type of spine (backbone).