Affection
Kindness, Love
When you have mercy upon those you love it's called affection. You end up doing things out of the kindness of your heart because they mean a lot to you.
じあい
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
彼女は慈愛に満ちた微笑を僕に向けた。
She turned her affectionate smile toward me.