rhymeless

from WordNet (r) 3.0 (2006)

rhymeless
    adj 1: not having rhyme; "writing unrhymed blank verse is like
           playing tennis without a net" [syn: {unrhymed},
           {unrimed}, {rhymeless}, {rimeless}] [ant: {rhymed},
           {rhyming}, {riming}]

from The Collaborative International Dictionary of English v.0.48

Rhymeless \Rhyme"less\, a.
   Destitute of rhyme. --Bp. Hall.
   [1913 Webster]