The only state of matter that is not a fuild is?

The solid state is not a fluid. The other three states, liquid, gas, and plasma, all have fluidic properties.

The four states of matter are solid, liquid, gas, and plasma. A fluid is a substance that has no fixed shape and yields easily to external pressure. This is the case with liquid, gas, and plasma phases. The solid phase, however, does not fit these parameters and that is obviously because it is not a fluid. So, the Solid phase is never a fluid.