The Collaborative International Dictionary of English v.0.48:

far-out \far-out\ adj.
   strikingly unconventional. [informal]

   Syn: kinky, offbeat, quirky, way-out.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

far-out
    adj 1: informal terms; strikingly unconventional [syn: far-
           out, kinky, offbeat, quirky, way-out]