[1] : The Collaborative International Dictionary of English v.0.48

infantile \in"fantile\ ?; 277, a. l. infantilis: cf. f.
   infantile. see infant.
   of or pertaining to infancy, or to an infant; similar to, or
   characteristic of, an infant; childish; as, infantile
   behavior.
   1913 webster
see also:
infant 

[2] : WordNet (r) 2.0

infantile
     adj 1: indicating a lack of maturity; "childish tantrums";
            "infantile behavior" syn: childish
     2: of or relating to infants or infancy; "infantile paralysis"
     3: being or befitting or characteristic of an infant;
        "infantile games"
see also:
childish 

[3] : Moby Thesaurus II by Grady Ward, 1.0

66 moby thesaurus words for "infantile":
   abecedarian, aboriginal, antenatal, autochthonous, babish, baby,
   babyish, beginning, budding, childish, childlike, creative,
   doll-like, dollish, elemental, elementary, embryonic, fetal,
   formative, foundational, fundamental, gestatory, immature, in arms,
   in diapers, in embryo, in its infancy, in nappies,
   in swaddling clothes, in the bud, in the cradle, inaugural,
   inceptive, inchoate, inchoative, incipient, incunabular, infant,
   infantine, initial, initiative, initiatory, introductory,
   inventive, juvenile, kittenish, nascent, natal, neonatal, newborn,
   original, parturient, postnatal, pregnant, prenatal, primal,
   primary, prime, primeval, primitive, primogenial, procreative,
   puerile, rudimental, rudimentary, ur

Infantile >> I Words
Infantile, definition of term: Infantile
infantile_pag1.html

Infantile Autis >> I Words
Infantile Autis, definition of term: Infantile Autis
infantile+autis_pag1.html