In Greek myth the hyacinth sprang from grief for a lost friend, so it is read as sorrow, regret and forgiveness. Its strong spring scent also ties it to playfulness and renewal.
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.