The term is a modern scientific compound, first used in the mid-20th century with the advent of spaceflight. The first element, "zero", traces a journey from the Arabic concept of emptiness (ṣifr) to the Italian mathematical term for the numeral, entering English to denote an absolute absence. The second element, "gravity", originates from the Latin "gravis" (heavy), embodying the fundamental force of attraction. Combined, they create a precise descriptor for the condition where the pervasive force of weight—central to human experience on Earth—is effectively nullified, as in orbital spacecraft.

Structure: zero (none) + gravity (gravitational force) - zero: From Italian "zero", ultimately from Arabic "ṣifr" meaning "empty, nothing". In this compound, it functions as a quantifying prefix meaning "having none of". - gravity: From Latin "gravitas" meaning "weight, heaviness", from "gravis" (heavy). In this compound, it functions as the core noun denoting the physical force.