English

isomass

From iso- + mass.

Formed from iso- + mass

Ancient Greek ἴσος ‘equal’

English iso-

Ancient Greek μᾶζα ‘barley-cake, lump of dough’

Latin massa ‘lump, dough’

Anglo-Norman masse

Middle English masse ‘lump, quantity of matter’

English mass

Today it means

noun A condition of having the same mass.

Language periods are conventional ranges, not dates for this word.