Gravest

The US invasion of Iraq was one of the gravest acts of aggression in modern history.

Hunting for ivory on the African continent has tripled, and elephants now are facing their gravest crisis in decades, according to the U.N. Environmental Protection Agency and other conservation groups.

"Thou wilt get an aged woman before thy years. Thou seemest ignorant of that best preservative of bright eyes and fresh looks — repose ; and unwittingly thou gravest a new wrinkle on thy brow, with each hour thou livest!"