noun
There was a mass of boulders at the bottom of the cliff
A mass of bills awaited my return from a trip abroad. Masses of people greeted us at the airport
A mass of sludge was clogging the valve
The great mass of the votes was still uncounted
The very mass of the elephant made it a hard target to miss
The taxes became burdensome and the masses rebelled
verb
Thunderclouds began to mass over the mountains
Thousands of people massed in front of the embassy. The massed bands made a tremendous noise
US