Rarely used alone; almost always appears in the negative expressions 他愛ない or 他愛もない, meaning 'trifling', 'silly', or 'unselfish' depending on context. The standalone noun sense 'altruism' is literary and uncommon.
The word 他愛 is normally used in the form 他愛ない.
There was altruism in his actions.
A Sino-Japanese compound of 他, “others,” and 愛, “love,” denoting love or concern for other people.