"Fog-laden" means covered in fog. From a mountaintop you'd be unable to see a river in a fog-laden valley, for example.
Fog is precipitation in cool air with a moisture laden mass. The moisture condenses, making air heavier. It begins to become visible air, or fog, nearest the surface of water or ground. This starts anywhere from sundown to sunup. With sunup, sunlight starts to warm the air. The condensation lowers; the density lowers. With lower density, the visible fog begins to rise. The fog wisps return to the sky to be a normal cloud.
It is not hyphenated.
When air becomes laden with moisture, the moisture condenses and becomes saturated. This cooler area of air begins to form fog at ground level or just above the ocean / water surface. If this is over ice flow or icebergs, the air also contains ice crystals in the fog. Like on land, the ice fog occurs evening to next morning. As the sun comes up, it warms the air, melts ice crystals, reduces the condensation, and like on land, the entire fog cloud or fog bank becomes lighter. The fog rises into the sky, becoming just one of the clouds.
Motorcycle is not hyphenated
No it's not hyphenated.
words are only hyphenated when they have a separate meaning when separated than they do when hyphenated
No, "hardworking" is not hyphenated.
Yes it should be hyphenated.
It can be. Some words can be seen both hyphenated and non-hyphenated.
"Field" is not hyphenated.
No they shouldn't be hyphenated.