religious

The word 'religious' originates from the Latin adjective religiosus, which itself derives from the noun religio. The core of religio is believed to stem from the verb religare, meaning 'to bind fast' or 'to tie back'. This literal sense of binding evolved to signify a bond of obligation, reverence, or piety between humans and the divine. Over time, the meaning broadened from describing a state of scrupulous observance of ritual duties to characterizing anything pertaining to organized systems of faith. The suffix '-ious' consistently forms adjectives, giving 'religious' its modern sense of being characterized by or devoted to such a binding system of belief and practice.

Structure: relig (to bind, obligation) + ious (adjective suffix) relig (Latin: religare, meaning to bind, to tie back) + ious (Latin-derived suffix forming adjectives meaning 'characterized by' or 'full of').