sylph

plural sylphs

1. human sciencesAn invisible being of the air.

   Her heart fluttered with expectation—her step was buoyant with hope, and she sprung into the carriage with the lightness of a sylph.

   1811, Mary Brunton, Self-Control

   1 more example

   Necromancy meant originally the conjuring up the souls of the dead, and later included the conjuring of all sorts of inhuman spirits such as sylphs, giants, and djinn.

   1941, Rupert Gleadow, Magic and Divination, page 125

   Synonyms: sylphid

2. The elemental being of air, usually female.
3. broadlyA slender woman or girl, usually graceful and sometimes with the implication of sublime station over everyday people.
4. biologyAny of the mainly dark green and blue hummingbirds (genus Aglaiocercus), the male of which has a long forked tail.