C.S. Lewis uses storge for the type of love he calls affection in The Four Loves.
In the book, Lewis discusses four Greek terms: storge, philia, eros, and agape. Storge describes natural affection, such as the warmth found among family members or people who share familiar daily life.
Lewis’s treatment is not a simple dictionary list. He examines how each form of love can be generous but also become distorted when treated as an absolute. His discussion combines classical vocabulary, Christian theology, observation, and literary examples.
Philia means friendship, eros refers to romantic or sexual love, and agape is associated with self-giving divine love. Because English usually uses one word—love—for all four, the Greek distinctions are easy to confuse.