A train whistle stands for an announcement of departure or arrival heard from a distance. Tradition reads it as a call to move, nostalgia for journeys past, or a signal that a moment is about to pass.
Does the traditional reading fit your dream, or did it mean something else to you?
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.