An intrusion is liquid rock that becomes solid under the Earth's surface.

The pavement of the yard was solid under my boots.

Her skin was solid and real under the blade.

It is one of the least reactive chemical elements, solid under standard conditions.

Jeff's hand was solid under my arm; he shoved me down in a seat.

One stepped by the diner's neon sign and became solid under the hard light.

She didn't know why or how, but the feeling was as solid as the ground under her feet.

Darmstadtium is expected to be a solid under normal conditions.

The ground on which I stand has ceased to be solid under my feet.

And hope that it is solid enough under the wheels.