Just like that, he can go from flat line to heart beat.

If there are too many flat lines, you have a problem.

This is indicated by a letter and number combination just before the flat line.

The graph for workers' pay is a flat line - in every sense.

The boulder shot across the water in a flat hard line.

But a one was just a straight line, anyway, kind of long and flat already.

In the last three or four hours, he said, the market was "almost a flat line" on the chart.

On the back was my address and a single flat line: Dealing with what?

Anthony's voice was a flat line; his eyes were half closed.

We are nearly on the flat line, if not already there.