Buddha-mind (Chinese foxing, Japanese busshin) refers to bodhicitta, "[the] Buddha's compassionate and enlightened mind," and/or to Buddha-nature, "the originally clear and pure mind inherent in all beings to which they must awaken."
Regarding awakening, Harold Stewart explains:
Busshin may also refer to Buddhakaya, the Buddha-body, "an embodiment of awakened activity."
Chan/Zen is also called foxin zong (Chinese) or busshin-shà « (Japanese), the "Buddha-mind school."