What is the etymology of "umbillical"
Executive summary
The adjective commonly spelled "umbilical" derives from Latin umbilīcālis, itself formed from Latin umbilīcus meaning "navel," plus the adjectival suffix -ālis; English borrowed the form in the mid-16th century (first attested c.1541) [1] [2] [3]. The deeper linguistic history threads through Latin back to an Italic and ultimately Indo‑European root that produced cognates across languages (Sanskrit, Greek, Germanic), while a parallel set of Germanic words for "navel" persisted in English via Old English nafela — a fact that explains the family of related words in English and other European tongues [4] [5].
1. The immediate source: New/Medieval Latin umbilīcālis
Modern reference works agree that "umbilical" is borrowed from New or Medieval Latin umbilīcālis, the form being transparently umbilic- (from umbilīcus, "navel") plus the Latin adjectival ending -ālis (rendering English -al); dictionaries record the borrowing and its medical/figurative senses entering English in the 1535–1545 period with a clear 1541 citation for the adjective [1] [3] [2].
2. The Latin noun umbilīcus and its formation
The Latin umbilīcus means "navel" or "central point" and is the stem from which the adjective is derived; etymologists trace umbilīcus to an earlier Italic form omb-el-īko- and analyse it as an Indo‑European derivative built on a base meaning something like "hub" or "central point" with an -l- formative and a noun‑forming suffix — a reconstruction summarized in standard dictionaries [4] [1].
**3. Indo‑European depth and cross‑family cousins**
Beyond Latin, etymological accounts show the PIE base h3n̥bh-(e)l- (or related reconstructions like h3nobh-) giving rise to a wide family of terms for "navel" or "center": Sanskrit nabhila, Avestan nafa, Persian naf, Greek omphalos, and various Germanic forms (Old Norse nafli, Old High German nabalo, German Nabel) — evidence that the concept and word‑family is archaic and pan‑Eurasian rather than a late Latin innovation [5] [4].
**4. Germanic route and Old English coexistence**
English preserved a native Germanic word for navel — Middle English navele < Old English nafela — which descends from Proto‑Germanic nabalan; etymological accounts (Harper/OED summaries) make clear that English therefore contains two overlapping streams: the native Germanic lexical line (navel, naval, etc.) and the learned Latinate line (umbilical, umbilicus) introduced via scholarly, medical, and ecclesiastical Latin in the Renaissance [5] [6] [2].
5. Forms, senses, and semantic spread
From its anatomical origin "pertaining to the navel," the Latinate adjective developed figurative senses (e.g., "central" or "vital link") and specialized technical uses in anatomy, embryology, geometry and later pathology; major dictionaries catalog the semantic broadening and note the noun form in English (umbilicus) appears later in citations than the adjective [2] [1] [7].
6. On the spelling "umbillical" and limits of the sources
The provided sources document "umbilical" (single‑l before the -ical ending) and the Latin umbilīcālis but do not document "umbillical" as an established variant; without explicit attestation in the cited dictionaries or etymological entries, it cannot be confirmed from these sources whether the double‑l spelling is historically attested, a typographic variant, or a modern misspelling — reporting is limited to the lexical forms the sources list [1] [2] [3].