A drain is where things disappear, read as letting go — or, when it gurgles back, as something returning you thought was gone. Climbing a drainpipe stands for an unconventional way out or in.
Does the traditional reading fit your dream, or did it mean something else to you?
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.