The word "thicket" is a native English formation, originating from the Old English adjective þicce, meaning dense or closely packed. The addition of the Old English diminutive suffix -et transformed the descriptive quality into a noun denoting a specific, compact physical object: a dense growth. This construction follows a common Germanic pattern where an adjectival root is nominalized to describe a place or thing characterized by that quality. Thus, the literal "small dense thing" evolved seamlessly into the modern meaning of a dense cluster of shrubs or small trees, perfectly capturing its impenetrable nature.

Structure: thick + et thick: From Old English þicce (dense, close, numerous). In this word, it functions as the core adjective meaning "dense". et: From Old English -et, a noun-forming suffix, often indicating a small or compact entity. It functions as a diminutive suffix.