Learner's definition of APPRECIATION
1 [noncount] : a feeling of being grateful for something
You've been so generous, and I'd like to show my appreciation by cooking a meal for you.
We'd like to present you with this gift in appreciation of your hard work. [=to show that we are grateful for your hard work]
2 [singular] : an ability to understand the worth, quality, or importance of something : an ability to appreciate something — usually + of or for 3 : full awareness or understanding of something — usually + of or for
4 [count] : a speech or piece of writing that praises something or someone 5 : an increase in the value of something
He bought the statue because he believed there would be an appreciation in its value.
Based on the history of the company, you can expect a significant appreciation in your investment over a number of years.