An aviary is read as many thoughts or voices gathered in one space. It can feel lively and abundant, or crowded and noisy, depending on the mood of the dream.
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.