A crater is the mark left by a great impact, read as the lasting trace of a shock or a powerful event. Dream books also see it as an empty space waiting to be filled with something new.
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.