An ambush is read as being caught off guard by a problem or a person you did not see coming, and as a call to notice what has been lying in wait.
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.