WordNet (r) 3.0 (2006):

dwell on
    v 1: delay [syn: dwell on, linger over]

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "dwell on":
   accent, accentuate, always trot out, bear in mind, belabor,
   breathe vengeance, brood over, cherish, continue, dawdle, drag out,
   draw out, dwell upon, emphasize, extend, fan the embers,
   give emphasis to, hammer away at, harbor revenge, harp on,
   have in mind, highlight, hold in mind, insist upon, italicize,
   keep, keep in memory, keep in mind, keep in view, labor, lengthen,
   lengthen out, linger on, overaccentuate, overemphasize, overstress,
   place emphasis on, point up, procrastinate, prolong, protract,
   punctuate, retain, rub in, spin out, spotlight, star, stress,
   stretch out, temporize, thresh over, treasure, underline,
   underscore, upon