nub
This term evokes a tactile sense of something small, blunt, and protruding. In a physical sense, it describes a remnant or a small bump, often implying that something larger has been worn away or that a small imperfection exists on a surface. When used figuratively, the word shifts from a physical protrusion to a conceptual center. It identifies the precise point where the most critical information resides, acting as the anchor for an entire argument or situation.
Meanings
The small, remaining piece of something after the rest has been used, cut, or worn away.
"He chewed the nub of the pencil until it snapped."
The central, most important, or essential point of a matter or argument.
"The nub of the problem is that we simply do not have enough funding."