WordNet (r) 3.0 (2006):

sweetie
    n 1: a person loved by another person [syn: sweetheart,
         sweetie, steady, truelove]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "sweetie":
   angel, babe, baby, baby-doll, beloved, buttercup, captive, catch,
   cherub, chick, chickabiddy, conquest, coquette, darling, date,
   dear, deary, doll, duck, duckling, flame, flirt, hon, honey,
   honey bunch, honey child, inamorata, ladylove, lamb, lambkin, love,
   lover, pet, petkins, precious, precious heart, snookums, steady,
   sugar, sweet, sweet patootie, sweetheart, sweetie pie, sweetkins,
   sweets, truelove, vamp, vampire