deep-set

The compound adjective "deep-set" is a relatively modern English formation, combining two native Germanic elements. The word "deep," with its ancient Proto-Indo-European root dʰeub- meaning "deep, hollow," conveys a sense of profound depth or recession. The participial form "set," from the Old English verb settan (to cause to sit, place, fix), implies a state of being firmly positioned. When combined, the literal imagery of eyes being "placed deeply" into the sockets evolved to describe a specific facial feature. This concrete meaning was later extended metaphorically to describe abstract qualities, such as feelings or beliefs, that are firmly and profoundly fixed within a person's character.

Structure: deep + set - deep: From Old English dēop (adjective), of Germanic origin; related to Dutch diep and German tief. In this compound, it functions as an intensifier describing the extent or degree. - set: From Old English settan (verb), of Germanic origin. In this compound, it functions as a participial adjective meaning "placed" or "fixed."