体

Lit. Body

Tai is the third component of Shin Gi Tai.

It consists of:

It forms the base of Good Sumou, i.e. it is understood that you have Tai, along with Gi, in order to develop Shin in order to excel in Sumou. Conversely, you cannot build Shin unless you possess Gi and Tai, which are the basics.

Tai is the complete base. Gi is the middle ground. And Shin is the pedestal on which Sumoudou resides.