avidity
eager desire or enthusiasm
Root
- avar / avid: craving, desire, eagerness, or greed
Other words with the avar / avid root
- avarice: greedy desire for wealth or gain
- avaricious: greedy for wealth or gain
- avid: eager, enthusiastic, or intensely interested
Avidity is desire as a noun: appetite, eagerness, hunger for more.
She attacked the practice set with the avidity of someone who finally saw progress.