Where does “いい” come from?
いい (Japanese) comes from Japanese 良い, from Japanese よし, from Old Japanese よ, from Japanese 夜, from Old Japanese よる, from Proto-Japonic yoru, from Proto-Japonic yo — night.
Ancestry of “いい”, step by step
| Step | Language | Word | Meaning |
|---|
| 1 | Japanese | 良い | good; easy; enough; not wanted any more |
| 2 | Japanese | よし | 縦し so-so; even if; 良し, 善し, 好し, 吉し, 佳し, 宜し all... |
| 3 | Old Japanese | よ | — |
| 4 | Japanese | 夜 | night, evening |
| 5 | Old Japanese | よる | — |
| 6 | Proto-Japonic | yoru | night |
| 7 | Proto-Japonic | yo | night |