sylph

Concise Oxford English Dictionary © 2008 Oxford University Press:
sylph /sɪlf/

▶noun

• 1 an imaginary spirit of the air.

• 2 a slender woman or girl.

• 3 a mainly dark green and blue hummingbird with a long forked tail. [Genera Aglaiocercus and Neolesbia.]

– derivatives
sylphlike adjective.

– origin C17: from mod. L. sylphes, sylphi and the Ger. pl. Sylphen, perh. based on L. sylvestris ‘of the woods’ + nympha ‘nymph’.