An Etymological Dictionary of Astronomy and Astrophysics

1. Either of the two limbs of a bird allowing her to fly. → Pegasus.
   

2. Either of the large flat structures in an aircraft’s body that provide the main source of lift.
   

3. In spectroscopy, same as → line wing.

Etymology (EN): M.E. wenge from O.N. vængr “wing of a bird, aisle, etc.” (cf. Dan., Swed. vinge “wing”).

Etymology (PE): Bâl “wing,” Mid.Pers. bâl, variant of par / parr “feather, " with the conversion of p to b and r to l; Av. parəna- “feather;” cf. Skt. parnam;
O.H.G. farn “fern;” PIE pornom “feather.”