Where does “nigellum” come from?

nigellum (Late Latin) comes from Latin nigellus, from Latin -lus, from Proto-Italic -elos, from Proto-Indo-European -e-lós, from Proto-Indo-European -lós — Forms agent nouns from verbal roots.

Ancestry of “nigellum”, step by step

StepLanguageWordMeaning
1Latinnigellussomewhat black
2Latin-lusAlternative form of -ulus; diminutive suffix
3Proto-Italic-elosForms desubstantival and deadjectival diminutive nouns
4Proto-Indo-European-e-lós—
5Proto-Indo-European-lósForms agent nouns from verbal roots
Every word from Proto-Indo-European -lós →Every word from Latin -lus →Every word from Proto-Italic -elos →