Well, for me this name is primarily associated with the little sister of Lord
Sebastian Flyte from Brideshead Revisited by
Evelyn Waugh.
Also in connection with the other persons in it, such as the mother Lady Marchmain, older sister
Julia or friend of the family
Charles Ryder and in particular of Lord
Sebastian.
This movie character has a sad, almost tragic fate, making the name "
Cordelia", the blue-blooded girl, in addition of the vintage vibe with a feeling of despondency, solicitousness, misery & joylessness.