The hem is where fabric is finished so it will not unravel, read as boundaries and loose ends. A falling hem is linked to something left unfinished that is starting to show.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.