曇る

1. Origins, structure, and basic meaning

• Structure: 曇る, read くもる, denotes an intransitive verb for a sky becoming overcast or glass fogging with vapor.
• Basic usage: It covers the sky becoming overcast and glasses fogging from warm soup.

2. Common pitfalls and similar expressions

• Overcast sky and fogged surface
  • Distinguish clouds obscuring the sky from vapor making a glass surface opaque.