Where does “sea unicorn” come from?

sea unicorn (English) comes from English unicorn, from Middle English unicorne, from Anglo-Norman unicorne, from Latin ūnicornis, from Latin ūni-, from Latin ūnus, from Old Latin oinos, from Proto-Italic oinos — one; single.

sea unicorn (English): The narwhal

Definitions

  1. The narwhal

Ancestry of “sea unicorn”, step by step

sea unicorn traces back through two separate lines of ancestry.

via English unicorn

StepLanguageWordMeaning
1EnglishunicornA mythical beast resembling a horse or deer with...
2Middle Englishunicorneunicorn; Any one-horned beast; anger, rage, fury,...
3Anglo-Normanunicorneunicorn
4LatinūnicornisOne-horned
5Latinūni-one; uni
6Latinūnusone, single
7Old Latinoinosone
8Proto-Italicoinoscardinal number 1 Previous: n/a Next: *duō;...
9Proto-Indo-Europeanóynosone; single

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 Proto-Indo-European óynos