ˌparēˈpa(ˌ)sü, -rə̇ˈp-; ˌpärēˈpä(ˌ)sü adverb (or adjective)
Etymology: Latin, with equal step
: at an equal rate or pace : with identical and simultaneous progression
the rate of development decreased pari passu with the density — Ecology
the two made a pari passu advance