'nonperiodic' originates from English, specifically from the negative prefix 'non-' (meaning 'not') combined with 'periodic' (from Greek 'periodikos' via Latin and French), where 'periodic' referred to something occurring at intervals.

'periodic' comes from Greek 'periodos' (meaning 'a going around', from peri- 'around' + hodos 'way'), passed into Latin and then Old French/Medieval Latin as 'periodicus/periodique' and into Middle English as 'periodic'; the modern English formation 'non-' + 'periodic' produced 'nonperiodic' in recent English usage.

Initially related to the idea of 'going around' or 'recurring at intervals'; 'nonperiodic' later developed as a transparent modern negative formation meaning 'not recurring at regular intervals', a meaning that has remained consistent.