Love means six symptoms. I give you something, you give me something. I give you something for eating, you also give me something for eating. Dadati pratigrhnati bhunkte bhojayate caiva guhyam akhyati prcchati. If I am in trouble, I express my mind, I open my mind before you, and you also try to help me. These are the six signs of love. That is Vedic civilization. Everything (is an) exchange of love.
Srila Prabhupada — Lecture, Los Angeles, 22nd June 1972