The Collaborative International Dictionary of English v.0.48:

Lithesome \Lithe"some\ (l[imac][th]"s[u^]m), a. [See Lithe,
   a., and cf. Lissom.]
   Pliant; limber; flexible; supple; nimble; lissom.
   [1913 Webster] -- Lithe"some*ness, n.
   [1913 Webster]