The horizon is the line you can always see and never reach, so tradition reads it as hope, aims and the future in general. A clear horizon is taken as a sense of direction; a hazy one as uncertainty.
Has this come up in your dreams before? What was going on in your life then?
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.