The hardening of concrete.    From Wordnet, Princeton University. 

His expression hardening, he opened them again and informed them, You should not have stayed!.    From Wordnik.com.  [WORLD OF WARCRAFT STORMRAGE] Reference

Rajamohan A, Sinclair BJ (2008) Short-term hardening effects on survival of acute and chronic cold exposure by.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

“Listen,” he said, inching in, his expression hardening, “there’s something not right about all of this.    From Wordnik.com.  [Nevermore] Reference

No, look within -- look at such a view of life as we were talking about, clamouring for "hardening" -- is that ours?.    From Wordnik.com.  [Three Dramas] Reference

Atherosclerosis is known as hardening of the arteries.    From Wordnik.com.  [IrishHealth.com] Reference

Atherosclerosis, an inflammatory immune disorder, is also referred to as hardening of the arteries.    From Wordnik.com.  [WebMD Health] Reference

This practice, known as hardening off, will enable seedlings to withstand exposure to the elements.    From Wordnik.com.  [Adirondack Daily Enterprise] Reference

When calcium builds up inside the arteries, it is typically referred to as hardening of the arteries.    From Wordnik.com.  [The World's Healthiest Foods] Reference

And the hardening is a function of whether you designed it to not be susceptible to this kind of pulse.    From Wordnik.com.  [CNN Transcript Oct 24, 2003] Reference

These hard, fibrous plaques prevent the artery from remaining flexible, creating what is called hardening of the arteries.    From Wordnik.com.  [Blogpulse Top Links] Reference

She stares at him—her expression hardening.    From Wordnik.com.  [A Life in Letters] Reference

“We?” demanded Holland, his expression hardening.    From Wordnik.com.  [The Blackstone Key] Reference

Judicious "hardening" means ample exposure of well-fed and well-clothed children.    From Wordnik.com.  [A Practical Physiology] Reference

Past "hardening" in the market has often come only after insurers have endured significant losses.    From Wordnik.com.  [Travelers Sounds Optimistic Note] Reference

Hydrogenation (commercially called "hardening") is one of the most well-known transformations of fats and oils.    From Wordnik.com.  [4 Jojoba Oil] Reference

But eventually, if you did it to an enormous degree, they would get a kind of hardening of the tissue around the area.    From Wordnik.com.  [CNN Transcript Dec 26, 2003] Reference

Probably there are some in the sample for whom this is just "hardening" their opposition to Obama, but even that is a big deal.    From Wordnik.com.  [Fox Poll: Nearly Two-Thirds Say Ayers Makes No Difference To Their Vote] Reference

Research shows laughter can help blood flow, preventing diseases such as hardening of the arteries, high blood pressure and strokes.    From Wordnik.com.  [CNN Transcript Aug 3, 2007] Reference

Research shows laughter can help blood flow, preventing diseases such as hardening of the arteries, high blood pressure, and strokes.    From Wordnik.com.  [CNN Transcript Nov 9, 2007] Reference

The common notion about "hardening" is a grievous delusion.    From Wordnik.com.  [Essays on Education and Kindred Subjects Everyman's Library] Reference

Having chronic conditions such as hardening of the arteries.    From Wordnik.com.  [بالاترین] Reference

Owl will use some of those "hardening" approaches in various parts of the system.    From Wordnik.com.  [Softpedia - Windows - All] Reference

Canada or Russia by "hardening" the air travel system against attacks, a Canadian officer said.    From Wordnik.com.  [FOXNews.com] Reference

We spent a couple of months making repairs and "hardening" the site against future copper theft.    From Wordnik.com.  [RWOnline] Reference

Life has a way of 'hardening' off our emotions just like a gardener in the spring with a tender plant.    From Wordnik.com.  [billingsgazette.com] Reference

Although it's been OK having the implants, I have experienced complications such as hardening and a loss of sensation.    From Wordnik.com.  [Lead Stories from AOL] Reference

Partly I believe in the conceit of showing off my own skill and daring, and partly by way of "hardening" Mrs. Bundle's nerves.    From Wordnik.com.  [A Flat Iron for a Farthing or Some Passages in the Life of an only Son] Reference

It turns out that turning off "user registration" is probably one of the simplest and most effective ways of "hardening" Wordpress.    From Wordnik.com.  [Blogposts | guardian.co.uk] Reference

I purposely refrain from further reference here to such measures as a methodical "hardening" by hydrotherapeutic procedures, and the like.    From Wordnik.com.  [The Sexual Life of the Child] Reference

"hardening" process of spending Christmas in a state of siege.    From Wordnik.com.  [Disturbed Ireland Being the Letters Written During the Winter of 1880-81.] Reference

"hardening" the air travel system against attacks, a Canadian officer said.    From Wordnik.com.  [Homepage] Reference

"hardening" the transmission lines and are considering double or back-up feeds.    From Wordnik.com.  [Latest news releases on Louisiana Politics, Business, Sports, Entertainment, Louisiana, USA and World News] Reference

"hardening" of its military policy through the widely criticized rocket launch.    From Wordnik.com.  [CTV News RSS Feed] Reference

"There's a kind of hardening not only of the body but of the mind through all this life out here.    From Wordnik.com.  [Mr. Britling Sees It Through] Reference

With international attitudes hardening, forget it.    From Wordnik.com.  [Reading The Leaders' Minds] Reference

Attitudes on both sides -- the upper class and the aggrieved masses -- are hardening quickly.    From Wordnik.com.  [Gloria's Poverty Problem] Reference