Definition - What does Metta mean?
Metta is a term that refers to one of the 10 perfections of Buddhism and is the first of the four Buddhist virtues, or "immeasurables." It can be translated as "benevolence," "loving," "friendship" or "kindness."
Metta means to care and wish well for another being without judging them, to accept them independently of agreeing or disagreeing with them, and without wanting anything from them in return. It is a universal love that can overcome all social, religious, ethnic, political and economic barriers. As a result of metta, one can experience another state of the four Buddhist virtues: joy, a true happiness in another's happiness.
Yogapedia explains Metta
Metta meditation, or cultivation of metta, is a popular Buddhist form of meditation. In the Theravada school of Buddhism, the yogi first cultivates their benevolence toward themselves; then toward their beloved family, friends and masters; then toward their enemies; and, ultimately, toward all living beings. In the Tibetan Buddhist school, a breathing technique is used where the yogi inhales love and benevolence and exhales distress and suffering.
Metta, together with the other three qualities from the four Buddhist virtues (compassion, joy and equanimity) were taught by both Buddha and the great sage, Patanjali, in his Yoga Sutras as qualities that must be developed and cultivated.