A serious act Dutch police are not allowed on their grounds.

This was the first serious act of rebellion.

Apprenticed to a London master, he ran away (a most serious act, as we shall see).

Leaders on both sides are operating in a fragile environment that they know can be disrupted by any serious act of terrorism.

Road rage is a relatively serious act: It may be seen as an endangerment of public safety.

Several officers were dismissed for corrupt acts far more serious than stealing a car battery.

"It seems that the court is looking at these cases more as social nuisances than serious criminal acts."

"Teenage prostitution" is not the only concept distinguishing between less and more serious illegal acts.

It was the most serious act of urban terrorism in six months.

In a statement issued after five days of investigation, the bureau characterized the incident as "a serious criminal act."