Being pinned down is read as feeling overpowered and unable to move freely. Dream books link it to pressure from a person or a situation that leaves little room to act.
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.