Thesaurus
mass
verb
Synonyms and Antonyms of MASS
to gradually form into a layer, pile, or mass <clouds massing on the western side of the mountain range>
Synonyms accrete, accumulate, amass, build up, concentrate, conglomerate, gather, mass, pile (up), stack (up)
Seen & Heard
What made you want to look up mass[verb]? Please tell us where you read or heard it (including the quote, if possible).