Where does “gullibleness” come from?

gullibleness (English) comes from English gullible, from English gull, from Middle English gulle, from Proto-Brythonic gwuɨlann, from Proto-Celtic wailannā, from Proto-Indo-European wai — oh!; woe!.

gullibleness (English): gullibility

Definitions

  1. gullibility

Ancestry of “gullibleness”, step by step

gullibleness traces back through two separate lines of ancestry.

via English gullible

StepLanguageWordMeaning
1EnglishgullibleEasily deceived or duped; naive, easily cheated...
2EnglishgullA seabird of the genus "Larus" or of the family...
3Middle Englishgullefriendly
4Proto-Brythonicgwuɨlannseagull, gull
5Proto-Celticwailannāseagull
6Proto-Indo-Europeanwaioh!; woe!

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 waiEvery word from Proto-Celtic wailannāEvery word from Proto-Brythonic gwuɨlann