The Collaborative International Dictionary of English v.0.48:

Legerity \Le*ger"i*ty\ (l[-e]*j[e^]r"[i^]*t[y^]), n. [F.
   l['e]g[`e]ret['e]. See 3d Leger.]
   Lightness; nimbleness. [Archaic] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

legerity
    n 1: the gracefulness of a person or animal that is quick and
         nimble [syn: agility, legerity, lightness,
         lightsomeness, nimbleness]