It was formed when rocks, weakened by gradual spreading of the North American continent, sagged into a wide, shallow trough.

The then controversial proposal was to channel the Brent into a concrete trough, possibly covered with a concrete lid, some 75 ft wide.

Clinging to his board, Ryan slid down the hunchbacked swell into the wide trough between waves.

Starting at 7 a.m., they built a trough 18 inches high and 6 feet 3 inches wide out of thick wood planks.

Out on the canyon's lip the sandstone had been worn into a shallow trough sixty feet wide.

There was a trough one and a half meters deep and twenty-three kilometers wide and less than six meters from them.

Fire lines are wide troughs dug by bulldozers and work crews to clear out trees, shrubs and underbrush.

The blue was very deep in the wide troughs.

At one end was a trough an inch wide and nearly as deep as the board was thick.

In his simulation, the ice cap has seven "arms" separated by wide troughs.