The English adjective "hollow," denoting something having a space or cavity inside, not solid, or lacking real significance or sincerity, traces its origins to Old English and ultimately to Proto-Indo-European roots. The earliest attested form in English is the Old English noun and adjective "holh," which referred to a hollow, a hole, a cave, or a concavity. This term was used to describe physical spaces that were empty or recessed, emphasizing the notion of an interior void.
"Holh" in Old English derives from the Proto-Germanic root *hulaz, which carried the meaning of "hollow" or "empty inside." This Proto-Germanic term is itself a descendant of the Proto-Indo-European root *ḱel- (also sometimes reconstructed as *kel-), which is generally understood to mean "to cover," "to conceal," or "to be hollowed out." The semantic development from the idea of covering or concealing to that of a hollow space is conceptually coherent: a covering or shell naturally implies an enclosed, empty interior.
The Germanic language family exhibits a rich set of cognates and derivatives stemming from this root, illustrating the breadth of its semantic field. Old English "hell," referring to the underworld, is etymologically connected through the idea of a concealed or covered place beneath the earth. Similarly, "hull," meaning the shell or empty case of a ship or seed, shares the root and highlights the concept of an outer covering enclosing an empty or hollow space. The word
The transition from the concrete physical sense of "hollow" to its metaphorical usage is a natural semantic extension. The adjective "hollow" came to describe not only physical objects that are empty inside but also abstract qualities such as insincerity or lack of substance. This metaphorical sense arises from the idea that something hollow may produce sound or appearance but lacks genuine content or depth. Thus, "hollowness" in a figurative sense conveys emptiness of meaning, value
It is important to distinguish the inherited Germanic lineage of "hollow" from any later borrowings or analogical formations. The Old English "holh" and its Proto-Germanic ancestor *hulaz represent a direct inheritance from the Proto-Indo-European root *ḱel-, without evidence of borrowing from other language families. The semantic field surrounding this root is consistent across Germanic languages, reinforcing the inherited nature of the term.
In summary, "hollow" is an inherited English word with deep Indo-European roots. Its earliest form, Old English "holh," descends from Proto-Germanic *hulaz, which in turn derives from the Proto-Indo-European root *ḱel-, meaning "to cover" or "to conceal." The word's development reflects a structural metaphor of a covering that creates an empty interior, a concept richly attested in related Germanic words. The adjectival sense of "hollow" as "not solid" or "empty inside" naturally extended to metaphorical meanings of insincerity or