safe; secure · safety; security

The security level, as established by the Department of Homeland Security, is orange.

You may injure yourself if you don't follow safety procedures.

To those who seek peace and security. We support you. And to all those who have wondered if America's beacon still burns as bright, tonight we proved once more that the true strength of our nation comes not from the might of our arms or the scale of our wealth, but from the enduring power of our ideals: democracy, liberty, opportunity and unyielding hope.

As time went on, rules were added to the game to make it safer.

A bus driver is responsible for the safety of the passengers.