'fleshliness' originates from Modern English, specifically formed from the adjective 'fleshly' + the suffix '-ness', where 'fleshly' meant 'of the flesh' and the suffix '-ness' formed nouns denoting a 'state or quality'.

'fleshliness' developed from Middle English forms such as 'fleshlichnesse' (from 'fleshlich'/'fleshly'), which in turn trace back to Old English 'flæsc' (or 'flæsclic' for related adjectival forms) meaning 'flesh'. Over time these forms regularized into the modern English 'fleshliness'.

Initially it referred broadly to 'the state or condition of the flesh' (bodily, corporeal), but over time the sense narrowed and diversified to include both 'meatiness/corpulence' and, metaphorically, 'sensuality' or 'carnal desire'.