[syn: copious, voluminous]
The Collaborative International Dictionary of English v.0.48:
Voluminous \Vo*lu"mi*nous\, a. [L. voluminosus: cf. F.
   volumineux.]
   Of or pertaining to volume or volumes. Specifically:
   [1913 Webster]
   (a) Consisting of many folds, coils, or convolutions.
       [1913 Webster]
             But ended foul in many a scaly fold,
             Voluminous and vast.                 --Milton.
       [1913 Webster]
             Over which dusky draperies are hanging, and
             voluminous curtains have long since fallen. --De
                                                  Quincey.
       [1913 Webster]
   (b) Of great volume, or bulk; large. --B. Jonson.
       [1913 Webster]
   (c) Consisting of many volumes or books; as, the collections
       of Muratori are voluminous.
       [1913 Webster]
   (d) Having written much, or produced many volumes; copious;
       diffuse; as, a voluminous writer.
       [1913 Webster] -- Vo*lu"mi*nous*ly, adv. --
       Vo*lu"mi*nous*ness, n.
       [1913 Webster]
WordNet (r) 3.0 (2006):
voluminous
    adj 1: large in volume or bulk; "a voluminous skirt"
    2: marked by repeated turns and bends; "a tortuous road up the
       mountain"; "winding roads are full of surprises"; "had to
       steer the car down a twisty track" [syn: tortuous,
       twisting, twisty, winding, voluminous]
    3: large in number or quantity (especially of discourse); "she
       took copious notes"; "a subject of voluminous legislation"
       [syn: copious, voluminous]
Moby Thesaurus II by Grady Ward, 1.0:
67 Moby Thesaurus words for "voluminous":
   Gargantuan, ample, amplitudinous, astronomical, awesome, big,
   billowing, boundless, broad, bulky, capacious, cavernous, colossal,
   commodious, comprehensive, copious, cosmic, deep, enormous,
   expansive, extended, extending, extensive, far-reaching, galactic,
   generous, gigantic, great, huge, immeasurable, immense, infinite,
   king-size, large, legion, loose, mammoth, massive, massy, monster,
   monstrous, monumental, mountainous, multifarious, multitudinal,
   multitudinous, numerous, outsize, overgrown, oversized, populous,
   prodigious, roomy, several, sizable, spacious, spreading,
   stupendous, substantial, sundry, titanic, tremendous, various,
   vast, weighty, wide, widespread