'regionally-contested' originates from the combination of 'regional' and 'contested'. 'Regional' comes from 'region', which originates from Latin 'regio', meaning 'direction, boundary, district'. 'Contested' comes from Latin 'contestari', meaning 'to call to witness'.

'Region' evolved from Latin 'regio' through Old French 'region', and 'contested' evolved from Latin 'contestari' through Old French 'contester'.

Initially, 'region' meant 'direction or boundary', and 'contested' meant 'to call to witness'. Over time, 'regionally-contested' evolved to describe disputes specific to a region.