Now chiefly Philos. Effort, endeavour; (now) esp. impulse, tendency.
1920 A. S. Pringle-Pattison Idea of God vxii. 325 The traditional form of the argument seems to represent the Creator as originating a material which has no relation to his purposes—which has no formative nisus in itself.1971 G. Urang Shadows of Heaven i. 34 He has only scorn for the idea that one must align himself with the nisus toward value in the evolutionary process.1986 Polit. Theory 14 200 Mediation between reason and imagination‥is set in motion by a dynamic nisus toward perfection.