EXAMPLES FROM THE WEB FOR LIFESAVER
It was a lifesaver, for he was shooting down into the darkness at a great rate.
He's been a lifesaver ever since he was a-put inter pants, but his jints is too stiff now.
Such a device, Tom felt, might prove to be a lifesaver if he should ever become trapped under water—perhaps far from help.
They'll probably patch it up and if we get a chance to escape later, it may be a lifesaver.