1. to remove mist or condensation from (a surface, especially a window or mirror)
Usage: third person singular present tense of 'demist'; common in British English; North American English more often uses 'defog'

Examples

• The car's rear window demists quickly on cold mornings.
• She demists the bathroom mirror with a towel after her shower.
• The heated windshield demists automatically when you turn on the defroster.
• He demists his glasses by breathing on them and rubbing them clean.
• The bathroom fan demists the mirror within a few minutes.