Where does “agate” come from?

agate (Basque) comes from Proto-Basque anate, from Latin Anas, from Latin ānus, from Kabuverdianu anos, from Portuguese nós, from Old Portuguese enos, from Old Portuguese os, from Vulgar Latin *lōs — that.

Ancestry of “agate”, step by step

StepLanguageWordMeaning
1Proto-Basqueanateduck
2LatinAnasduck
3Latinānusa ring
4Kabuverdianuanoswe, first person plural
5Portuguesenóswe; us; "first-person plural objective personal...
6Old Portugueseenos
7Old Portugueseosthe
8Vulgar Latin*lōs
9Latinillōs
10Latinillethat; those; "; demonstrative pronoun "; that...
11LatinolleArchaic form of ille
12Proto-Italic*olnosthat
Every word from Proto-Italic *olnosEvery word from Latin olleEvery word from Latin ille