nec unus

Latin

From nec +‎ ūnus. Documented in Late Latin from at least the fifth century CE.^[1]

nec ūnus (feminine nec ūna, neuter nec ūnum); indeclinable portion with a first/second-declension adjective (Late Latin)

Balkano-Romance:
- >? Romanian: niciun
Italo-Dalmatian:
- Dalmatian: nenčoin
- Istriot: ningun
- Italian: neguno, niguno (archaic or regional), neuno, niuno, gniuno (if not from "nē ūnus")
- Old Venetan: negun
Rhaeto-Romance:
- Ladin: degun
Gallo-Italic:
- Lombard: negun, nigun
  Bergamasco: nehu, nigu
- Piedmontese: niun, nengun
Northern Gallo-Romance:
- Franco-Provençal: nion, nengun, negun
  Valdôtain: gneun
- >? Old French: neisun
Southern Gallo-Romance:
- Catalan: ningú, dingú
  Balearic: nengú, digú
  Majorcan: negú, nigú
  
  Northwestern: nengú
  
  Valencian: nengú, degú, digú
- Occitan: degun (all dialects)
  Auvernhat: dengun
  
  Gascon: digun
  
  Lengadocian: digun
Ibero-Romance:
- Aragonese:
  Central: dingun
  
  Ribagorçan: dengú, degú, digú
  
  Western: ningun, nengún
- Asturian: dengún, denguno, dingún, dinguno, nengún, nenguno
- Old Galician-Portuguese: niun, niũu, neũu, neun, ningũu, ningũu, ningun, nengũu, nengun, nen (h)ũu, nin (h)ũu
  - Fala: niñún
  - Galician: nengún, ningún, neñún, niñún
  - Portuguese: nenhum, nengum (northern)
- Spanish: ningún, ninguno

AIS: Sprach- und Sachatlas Italiens und der Südschweiz [Linguistic and Ethnographic Atlas of Italy and Southern Switzerland] – map 1597: “non lo trovo in nessun luogo” – on navigais-web.pd.istc.cnr.it
ALF: Atlas Linguistique de la France^[1] [Linguistic Atlas of France] – map 1665: “personne ne me croit” – on lig-tdcge.imag.fr
Meyer-Lübke, Wilhelm (1911) “nĕc ūnus”, in Romanisches etymologisches Wörterbuch (in German), page 435
Misión lingüística en el Alto Aragón - Joseph Saroïhandy

^ Gianollo, Chiara. 2020. Grammaticalization parameters and the retrieval of alternatives: Latin nec from discourse connector to uninterpretable feature. In Gergel, Remus & Watkins, Jonathan (eds.), Quantification and scales in change, 47–48. Berlin: Language Science Press.