massless

the word 'massless' is a modern scientific compound, primarily used in physics. its first element, 'mass', derives from the latin 'massa', which originally meant a lump of dough or a shapeless bulk, a concept that evolved to denote the physical property of matter. the second element, '-less', is a productive english suffix of germanic origin, used to form adjectives indicating the absence of a quality. the combination literally means 'without mass', a concept that became necessary with the development of modern physics to describe entities like photons, which possess energy and momentum but no rest mass.

Structure: mass (mass) + less (without) mass (from latin 'massa', meaning 'lump, bulk, substance') + less (from old english '-lēas', an adjective-forming suffix meaning 'devoid of, free from').