caved-in

The compound adjective "caved-in" is built upon the literal image of a cave or hollow structure collapsing inward upon itself. The root "cave" originates from the Latin cavus, meaning "hollow," which itself can be traced back to the Proto-Indo-European root keuə-, meaning "to swell" or "to be vaulted," a concept that evolved to describe an arched hollow space. The adverbial particle "in," of Germanic origin, specifies the direction of the collapse. Over time, this vivid physical description was metaphorically extended to describe a person who has collapsed under pressure or yielded, much like a structure giving way and falling inward, perfectly linking the concrete action to the abstract sense of surrender.

Structure: cave (hollow) + in (preposition/adverb) - cave: From Latin cavus (hollow, a hollow place). Functions as the core root, providing the central concept of a hollow space or cavity. - in: From Old English in (in, into, within). Functions as a particle/adverb, indicating a direction or state of being inward.