The Collaborative International Dictionary of English v.0.48:

Enrichment \En*rich"ment\, n.
   The act of making rich, or that which enriches; increase of
   value by improvements, embellishment, etc.; decoration;
   embellishment.
   [1913 Webster]

WordNet (r) 3.0 (2006):

enrichment
    n 1: act of making fuller or more meaningful or rewarding
    2: a gift that significantly increases the recipient's wealth

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "enrichment":
   Great Leap Forward, advance, advancement, amelioration, amendment,
   ascent, augmentation, bettering, betterment, boost, complement,
   enhancement, eugenics, euthenics, fecundation, fertilization,
   fortification, furtherance, headway, impregnation, improvement,
   insemination, lift, melioration, mend, mending, pickup, preferment,
   progress, progression, promotion, recovery, restoration, revival,
   rise, upbeat, uplift, upping, upswing, uptrend, upward mobility,
   vitaminization