| Webster's Online Dictionary |
| Expressions | Domain | Definition | |
| Blue-sky scale | Aerospace | = Linke scale. (references) | |
| Blue-sky scale | Geography | Scale of nine standardized shades, from white to ultramarine, used to estimate by comparison the color of the blue of the sky. Source: European Union. (references) | |
Source: compiled by the editor from various references; see credits. | Top | ||
