appreciation in WordNet English dictionary

1. a favorable judgment
   "a small token in admiration of your works"
   admiration  appreciation 
   
2. an increase in price or value
   "an appreciation of 30% in the value of real estate"
   appreciation 
   
3. understanding of the nature or meaning or quality or magnitude of something
   "he has a good grasp of accounting practices"
   appreciation  grasp  hold 
   
4. delicate discrimination (especially of aesthetic values)
   "arrogance and lack of taste contributed to his rapid success"; "to ask at that particular time was the ultimate in bad taste"
   taste  appreciation  discernment  perceptiveness 
   
5. an expression of gratitude
   "he expressed his appreciation in a short note"
   appreciation