I felt my eyes narrow and my entire face become rigid.

Twelve hours after death, the muscles have become fully rigid.

He froze in place, becoming more rigid and still than the trees that surrounded him.

Syntax was also simplified somewhat, with word order patterns becoming more rigid.

Then, slowly, his face began to change, becoming less rigid, more at peace.

This may mean becoming even more rigid and defensive about receiving help.

The precise predictability and stability of the system is partly why it has become too rigid.

It is a fact that intellectual and social barriers are becoming ever more rigid.

In more and more countries, the rules concerning work are gradually becoming less rigid.

If the tendons in the toe become rigid, they press the joint out of alignment.