1. [n]  a small tuft or lock; "wisps of hair"
2. [n]  a flock of snipe
3. [n]  a small bundle of straw or hay
4. [n]  a small person; "a mere wisp of a girl"

1. \Wisp\, n. [OE. wisp, wips; probably akin to D. & G. wisch,
   Icel. visk, and perhaps to L. virga a twig, rod. Cf. {Verge}
   a rod, {Whisk}, n.]
   1. A small bundle, as of straw or other like substance.
            In a small basket, on a wisp of hay.  --Dryden.
   2. A whisk, or small broom.
   3. A Will-o'-the-wisp; an ignis fatuus.
            The wisp that flickers where no foot can tread.
                                                  --Tennyson.
   

2. \Wisp\, v. t. [imp. & p. p. {Wisped}; p. pr. & vb. n.
   {Wisping}.]
   1. To brush or dress, an with a wisp.
   2. To rumple. [Prov. Eng.] --Halliwell.
   

["An Experiment with a Self-Compiling Compiler for a Simple List-Processing Language", M.V. Wilkes, Ann Rev Automatic Programming 4:1-48. (1964)].