means The state of being accountable for something — a duty, task, or outcome that's yours to handle and answer for.

from From the Latin respondere, 'to answer, to respond' (re-, 'back,' plus spondere, 'to pledge'). The same spondere gives us 'spouse' and 'sponsor' — all rooted in the idea of a solemn promise. So a responsible person is, quite literally, one who can be called upon to answer back, pledge in hand. The abstract noun 'responsibility' is a comparatively late arrival, an 18th-century coinage built from the older adjective 'responsible.'