As the last letter, Z is read as an ending, a final step or the completion of a long sequence. Its zigzag also stands for a route that changes course more than once.
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.