oh! I'm pretty sure lilac flowers are edible, (make sure to clean them if you use) maybe make sure just in case? Double checking won't do any harm. I've heard that you could soak them in water and then drink it?
They are associated with a nymph from Greek mythology I think,, her name is Syringa. She turned herself into a lilac bush to escape Pan because he had frightened her.
Also I've heard it can be connected to spirituality and the third eye chakra because of it's color!
Good luck I hope you can make use of it, they are lovely flowers,
Lilac can be utilized in protection magic as a ward as well as an aid in banishing magic. Simply planted on a property adds protection from harm and wards off evil spirits. Some say the buds/flowers placed in a haunted building will banish the spirits. This however is only true for evil or negative spirits. Lilac flowers can also aid in divination and clairvoyance abilities. The aroma or the fresh buds or the essential oil can be utilized while in meditation, scrying, throwing the cards/runes, or any other form of divination.
Lilac can also be used in love, peace, and harmony magic. The buds maybe used as well as the wood of the bush. A wand can be made from Lilac wood for magic that is related to love, peace, and harmony. Lilac wood however is not ideal for other purposes such as banishing or protection.