The Collaborative International Dictionary of English v.0.48:

Tangly \Tan"gly\, a.
   1. Entangled; intricate.
      [1913 Webster]

   2. Covered with tangle, or seaweed.
      [1913 Webster]

            Prone, helpless, on the tangly beach he lay.
                                                  --Falconer.
      [1913 Webster]