precocious Antonyms

retarded moronic outmoded feebleminded unsophisticated tardy stupid simple serotinous rudimentary nonprogressive unprogressive underdeveloped ponky worsened not the sharpest tool in the shed feather-brained dumb as dirt dumb as a box of rocks dim-witted altricious undeveloped ass-headed primitive overdue dated callow belated behindhand backward archaic antique antiquated antediluvian delayed delinquent imbecile outdated old-fashioned old obtuse obsolete low latish late immature ancient