WordNet (r) 3.0 (2006):

natal day
    n 1: the date on which a person was born [syn: birthday,
         natal day]

Moby Thesaurus II by Grady Ward, 1.0:

33 Moby Thesaurus words for "natal day":
   anniversary, annual holiday, bicentenary, bicentennial, biennial,
   birthday, bissextile day, centenary, centennial, commemoration,
   decennial, diamond jubilee, golden wedding anniversary, holy days,
   immovable feast, jubilee, leap year, name day, octennial,
   quadrennial, quasquicentennial, quincentenary, quincentennial,
   quinquennial, septennial, sesquicentennial, sextennial,
   silver wedding anniversary, tercentenary, tercentennial,
   tricennial, triennial, wedding anniversary