Where does “jackassness” come from?

jackassness (English) comes from English jackass, from English Jack, from Middle English jakke, from Anglo-Norman jacke, from Middle French jaque, from Middle French jacques, from French jacques, from Latin Iacobus — heel of the foot; heel.

jackassness (English): foolishness; idiocy

Definitions

  1. foolishness; idiocy

Ancestry of “jackassness”, step by step

jackassness traces back through two separate lines of ancestry.

via English jackass

StepLanguageWordMeaning
1Englishjackassa male donkey; a foolish or stupid person; an...
2EnglishJackA placeholder or conventional name for any man,...
3Middle EnglishjakkeA padded coat, especially as light armour
4Anglo-Normanjacke
5Middle Frenchjaque
6Middle Frenchjacques
7Frenchjacquesplural of jacque; a stupid person; a jemmy or...
8LatinIacobusJacob; James; Saint James
9Ancient GreekἸάκωβος
10Ancient GreekἸακώβJacob
11HebrewיַעֲקֹבJacob
12Hebrewעָקֵבheel of the foot; heel

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 Hebrew עָקֵב