Definition - What does Maitri mean?
Maitri is a Sanskrit word which can be translated as "friendship," "friendliness" or "benevolence." It can also be used to describe the mental union that takes place when two people are on the same wavelength. The Pali version of this word that is often used is metta.
Another way of describing maitri is a form of love which excludes the suffering that can arise from attachment (known as upadana).
Yogapedia explains Maitri
For many people who meditate while practicing yoga, the cultivation of friendliness or benevolence is one of the main aims, especially in Buddhist culture. This process begins with the idea of being benevolent to oneself before extending this to eventually cover all sentient beings.
Yogis who are seeking an enriching experience that adds greatly to one's quality of life may want to consider the concept of maitri the next time they plan to explore meditation.