Search Result for "ribless": 
Wordnet 3.0

ADJECTIVE (1)

1. having no ribs or no visible ribs; 



The Collaborative International Dictionary of English v.0.48:

Ribless \Rib"less\, a.
   Having no ribs.
   [1913 Webster]


WordNet (r) 3.0 (2006):

ribless
    adj 1: having no ribs or no visible ribs [ant: ribbed]