Pema Chodron writes in The Heart of the Matter: How to Live with Compassion and Courage:

Bodhi means “awake” and citta means “heart-mind.” Bodhicitta is a longing, a yearning, that comes to fortunate people to wake up, and specifically to wake up so they can be of help to other people and to the earth. It’s very common that people want to be free of suffering and go about it in ways that just increase their suffering. But it’s less common for people to want to be free of suffering because they really have a longing to help.