I LOVE this name, it's a perfect unisex name and so unique. And it rolls off the tongue so nicely when you say it. I'm completely sold, I think I might have to change my name to this honestly.
When I hear this name, I first think of the surname Halcyon from Star Wars, among whose members include Jedi Masters Corran Horn and Nejaa Halcyon. Then I think of Halcyon Green from the Percy Jackson series. In both cases, Hal is used as a nickname for this name (i.e. Hal Horn, Hal Green). This is actually the first time I've ever heard it as a feminine name; I always thought it was masculine.
Ellie Goulding has an album called Halcyon. This would be very, very strange as a name. It really doesn't sound like one. The word Halcyon also means a good memory from the past.
― Anonymous User 6/10/2013
-5
Spelled Halcion, it's a well-known sleeping pill used to treat severe insomnia. Serial killer Jeffrey Dahmer used Halcion or a generic version to drug his victims.
From Latin Alcyone, daughter of Aeolus and wife of Ceyx. When her husband died in a shipwreck, Alcyone threw herself into the sea whereupon the gods transformed them both into Halcyon birds (kingfishers). When Alcyone made her nest on the beach, waves threatened to destroy it. Aeolus restrained his winds and made the waves be calm during seven days in each year, so she could lay her eggs. These became known as the "Halcyon Days", when storms never occur.