Where does “deleteriousness” come from?

deleteriousness (English) comes from English deleterious, from Medieval Latin deleterius, from Ancient Greek δηλητήριος, from Ancient Greek δηλητήρ, from Ancient Greek -τήρ, from Proto-Indo-European -tḗr — Derives agent nouns from verbs, denoting someone...

deleteriousness (English): The quality of being deleterious

Definitions

  1. The quality of being deleterious

Ancestry of “deleteriousness”, step by step

deleteriousness traces back through two separate lines of ancestry.

via English deleterious

StepLanguageWordMeaning
1EnglishdeleteriousHarmful often in a subtle or unexpected way;...
2Medieval Latindeleterius
3Ancient Greekδηλητήριοςharmful, damaging, destructive; mischievous
4Ancient Greekδηλητήρdestroyer
5Ancient Greek-τήρAdded to verb stems to form masculine agent nouns
6Proto-Indo-European-tḗrDerives agent nouns from verbs, denoting someone...

via English Ness

StepLanguageWordMeaning
1EnglishNessAn Ulster princess and the mother of Conchobar mac Nessa and Findchoem in the Ulster Cycle of Irish mythology. Daughter of Eochaid Sálbuide. Also the mother of Cormac Cond Longas by incest with Conchobar mac Nessa
2Middle Englishnesse
3Old Englishnæsnot, not at all; not; first/third-person singular...
4Proto-Germanicnasjąfoothill; headland; cape
5Proto-Indo-Europeannéh₂snose
Every word from Proto-Indo-European -tḗrEvery word from Ancient Greek -τήρEvery word from Ancient Greek δηλητήρ