Where does “sea chestnut” come from?

sea chestnut (English) comes from English chestnut, from English chesten, from Middle English chesteyne, from Old French chastaigne, from Old English ċisten, from Latin castanea, from Ancient Greek καστάνεια, from Ancient Greek κᾰ́στᾰνᾰ — sweet chestnuts; chestnut.

sea chestnut (English): A sea urchin

Definitions

  1. A sea urchin

Ancestry of “sea chestnut”, step by step

sea chestnut traces back through two separate lines of ancestry.

via English chestnut

StepLanguageWordMeaning
1EnglishchestnutA tree or shrub of the genus "Castanea"; The nut...
2EnglishchestenA chestnut; A chestnut-tree
3Middle EnglishchesteyneA chestnut tree; A chestnut; the nut of the...
4Old Frenchchastaignechestnut
5Old Englishċistenchestnut
6Latincastaneaa chestnut tree; a chestnut
7Ancient GreekκαστάνειαAlternative form of κᾰ́στᾰνᾰ; chestnut
8Ancient Greekκᾰ́στᾰνᾰsweet chestnuts; chestnut

via English sea

StepLanguageWordMeaning
1EnglishseaA large body of salt water; A lake, especially if...
2Middle Englishseesea, ocean; A body of water, a lake; seat, chair
3Old Englishsea, lake
4Proto-West Germanicsaiwisea
5Proto-Germanicsaiwizsea, ocean
6Proto-Germanicsīhwanąto filter
7Proto-Indo-Europeanseykʷ-to moisten; to filter
8Proto-Indo-Europeansey-to be wet; dribble; run; to stretch one's arm;...
Every word from Ancient Greek κᾰ́στᾰνᾰ