Fraught means filled with something — often something bad. Your Thanksgiving was fraught with awkward moments when your family saw your blue hair, and it only got worse when you told them you'd quit law school to join the circus.
Fraught is related to the word freight, and comes from the Middle English fraughten, meaning "to load with cargo." Think of a cargo ship loaded up with freight for a journey — it's full of supplies, just like Thanksgiving was filled with — or fraught with — awkward moments. Fraught can also describe a situation filled with distress. If relations between two countries are fraught, they are not getting along with each other.