This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Be careful of the ねっ portion (normally is ねつ).
The child was practicing hiragana with zeal.
My heart was struck by how he practiced skipping enthusiastically every morning in front of the station.
Tofugu’s new employees were all keen to show their enthusiasm and worked even when they could have been sleeping.