sylphide = femme gracieuse et légère (Larousse)
die Sylphide = 1. weiblicher Luftgeist; 2. zartes, anmutiges Mädchen (Duden)
sílfide = 1. f. Según los cabalistas, ser fantástico o espíritu elemental del aire (RAE)
sylph = 1. a slender graceful girl or young woman; 2. any of a class of imaginary beings assumed to inhabit the air (Collins)