stiffen

Traditionally, the way to stiffen a polymer network is to add more crosslinks.

Over time, the valve thickens and stiffens, making the heart work harder to pump blood effectively around the body.

Certainly, the competition level stiffened recently with Indiana and Ohio State handing the Cornhuskers losses in their two most recent games.

Opponents argue that by stiffening penalties we’ll refill our prisons after having dramatically reduced their populations to meet a federal court order.

He said his parents also told him their child had been unwell the night before he was brought to hospital and had been displaying abnormal movements including shaking and stiffening of his limbs.