The Collaborative International Dictionary of English v.0.48:

Anfractuous \An*frac"tu*ous\, a. [L. anfractuosus, fr. anfractus
   a turning, a winding, fr. the unused anfringere to wind,
   bend; an-, for amb- + fractus, p. p. of frangere to break:
   cf. F. anfractueux.]
   Winding; full of windings and turnings; sinuous; tortuous;
   as, the anfractuous spires of a horn. --
   An*frac"tu*ous*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

anfractuous
    adj 1: full of twists and turns; "anfractuous cliffs"

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "anfractuous":
   ambagious, circuitous, circumlocutory, cochlear, cochleate,
   convoluted, convolutional, corkscrew, corkscrewy, flexuose,
   flexuous, helical, helicoid, involute, involuted, involutional,
   labyrinthine, mazy, meandering, meandrous, rivose, rivulose,
   roundabout, ruffled, screw-shaped, scrolled, serpentine, sinuate,
   sinuose, sinuous, snaky, spiral, spiroid, torsional, tortile,
   tortuous, turbinal, turbinate, turning, twisting, twisty,
   verticillate, volute, voluted, whorled, winding, wreathlike,
   wreathy