Aside from a rigid structure to the day, personal activity was also regulated.

All that vast power kept in check by their rigid societal structure.

The world of work, through their eyes, has the same rigid structure.

For this reason neutronium does not form a rigid structure.

The horse hoof is not at all a rigid structure.

The rest of the hull was still open to air, but eventually the rigid structure would be covered and firm.

Now the elevator, like any piece of engineering, isn't a completely rigid structure.

Also it must be said that sometimes the more rigid structure of the constellation is desired.

Most of them are highly idiosyncratic, too much so to be able to function within a rigid military structure.

Much like the old world, colonial America was divided into a rigid social structure.