The Collaborative International Dictionary of English v.0.48:

Toddler \Tod"dler\, n.
   One who toddles; especially, a young child. --Mrs. Gaskell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

toddler
    n 1: a young child [syn: toddler, yearling, tot,
         bambino]

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "toddler":
   babe, baby, baby bunting, bambino, incubator baby, infant,
   little angel, little darling, mewling infant, neonate, nursling,
   papoose, preemie, premature baby, preschooler, puling infant,
   suckling, weanling, yearling