A canal is water made to follow a set course. Tradition reads it as emotions that have been directed and contained — calm and useful, though sometimes too tightly controlled.
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.