An edge marks the end of the familiar, so it stands for limits, risk and thresholds. Standing at one is read as a decision point; walking along it, as living close to a boundary you can feel.
Where in your waking life have you met something like this lately?
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.