'paralyze' originates from Greek, specifically the verb 'paráleyein' (and the noun 'parálusis'), where 'para-' meant 'beside' or 'alongside' and 'lyein' (from Greek 'luō') meant 'to loosen' or 'to release'.

'paralyze' passed into Late Latin and Medieval Latin as 'paralisis'/'paralysis', then into Middle English (paralysen), and eventually became the modern English verb 'paralyze'.

Initially it meant 'to loosen beside' in the literal Greek sense (loss of control), but over time it evolved into the medical and figurative sense 'to deprive of movement or ability to act', which is the modern meaning.