pari passu /ˌpa.ɹiˈpɑː.suː/adverb 2adjective 1 adverb2 •Simultaneously; likewise, equally.Pari passu with Marechal Bugeaud's ‘pacification’, French colonisers steadily took root in Algeria. — 1977 •At an equal rate. adjective1 •At an equal rate.