梵語瑜伽Yoga，譯曰相應。真言宗之異名。彼宗以三密相應之旨為本，故曰瑜伽宗，又云相應宗。
Yoga, the sect of mutual response between the man and his object of worship, resulting in correspondence in body, mouth, and mind, i. e. deed, word, and thought; it is a term for the Shingon or 真言 school.
真言宗的別名，因真言宗是以三密相應為旨趣。