the body, substance, object, reality
體 centers on the physical form or structure of something: the body, a tangible object, or the underlying substance of reality.
體 combines 骨 (bone) with 豊, which likely contributes the sound and the idea of a ritual vessel, together suggesting the physical framework or body.
The left side 骨 means bone, the body's framework. The right side 豊 looks like a full ritual vessel, suggesting substance. Together, 體 is the body as a tangible, structured object.
For タイ, imagine tying a ribbon around the body: tie -> タイ, and the ribbon wraps around the physical form of 體.