What is a splinter referring to?

Answer 1

A splinter is a sharp slender fragment that is broken from a larger piece of material. The common use describes a small shard of wood, metal, or glass that can stick into your skin and require removal.

The verb to splinter likewise means to break partly or entirely into small pieces, as would occur if a wood door was impacted by a sledge hammer. The similar term shatter is used for glass.

Two modern terms are "splinter cell" and "splinter group."

A splinter cell is a small part of a larger group that operates automonously, often without direction from the parent group.

A splinter group is a split-off subgroup that no longer follows the direction of its original body, due to differences in philosophy or focus.