Words may be hidden in the grid that start with path notation composed of LRUD, then the starting letter, then the letters reached by traveling along the path. For example, if the word DREAM was hidden, the starting point would be E, directly below it would be an A, and immediately to the right of that A would be an M. Two nine-letter words are hidden in the completed grid that start at the same place. The meta solution is to type both of these hidden words, in either order.
Woah, this was very cool. Kinda shocked I got it, although there are a decidedly finite number of 9 letter words that start with some combination of only the letters DRUL, and once I found a sensible starter (LULL) the first one fell into place nicely. The second was way harder to find, even knowing that I'm starting at the A- I'm not even sure why I know the word ULULATION. I've definitely never said it out loud!