The Collaborative International Dictionary of English v.0.48:

Verso \Ver"so\, n. [L. versus, p. p. of vertere to turn: cf. F.
   verso.] (Print.)
   The reverse, or left-hand, page of a book or a folded sheet
   of paper; -- opposed to recto.
   [1913 Webster]

WordNet (r) 3.0 (2006):

verso
    n 1: left-hand page [ant: recto]
    2: the side of a coin or medal that does not bear the principal
       design [syn: reverse, verso] [ant: obverse]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "verso":
   Gospel side, acknowledgments, back, back matter, bastard title,
   bibliography, cantorial side, catch line, catchword, colophon,
   contents, contents page, copyright page, dedication, endleaf,
   endpaper, endsheet, errata, flyleaf, folio, fore edge, foreword,
   front matter, half-title page, head, imprint, index, inscription,
   introduction, larboard, leaf, left, left hand, left wing,
   left-hand side, left-winger, liberal, makeup, near side, page,
   port, port tack, portside, preface, preliminaries, radical, recto,
   reverso, running title, signature, subtitle, table of contents,
   tail, text, title, title page, trim size, type page, wrong side