The Collaborative International Dictionary of English v.0.48:

Ligsam \Lig"sam\ (l[i^]g"sam), n. [Cf. D. liggen to lie, E. lie
   to be prostrate, and E. flotsam, jetsam, or ligan.]
   Same as Ligan. --Brande & C.
   [1913 Webster] Ligulae