"It Depends."
The usual meaning I expect you'd see is the texture lookup instructions in pixel shaders. The translation of these is "Given this texture index and these texel coordinates, fetch the correct bits of memory, apply any filtering, and output a value for further processing."
There could be others (e.g. inside the OpenGL driver it can be the action of converting a texture name as supplied by the application to a texture information struct) but I imagine this is what you want.
