What is another word for fog up?
Pronunciation: [fˈɒɡ ˈʌp] (IPA) 
When it comes to synonyms for the phrase "fog up", a few different options come to mind. One possibility is "steam up", which is often used to describe a situation where fog or condensation appears on a surface due to heat or moisture. Another option might be "cloud up", which can be used in a similar context to describe a situation where a surface becomes obscured by fog or clouds. Finally, you might consider "mist over" as another potential synonym. This phrase also describes a situation where a surface becomes cloudy or obscured by mist or fog. Ultimately, the choice of synonym will depend on the specific context and intended meaning of the phrase.
