'irregularly-sectioned' originates from the combination of 'irregularly' and 'sectioned'. 'Irregularly' comes from the Latin 'irregularis', where 'in-' meant 'not' and 'regularis' meant 'rule'. 'Sectioned' comes from the Latin 'sectio', meaning 'a cutting'.

'Irregularis' transformed into the Old French 'irregulier', and eventually became the modern English word 'irregular'. 'Sectio' transformed into the Old French 'section', and eventually became the modern English word 'sectioned'.

Initially, 'irregular' meant 'not conforming to a rule', and 'sectioned' meant 'divided into parts'. Together, they describe something divided in a non-uniform manner.